diff --git a/inc/Module/Build/Sqitch.pm b/inc/Module/Build/Sqitch.pm
index 27d93aa6..a711338e 100644
--- a/inc/Module/Build/Sqitch.pm
+++ b/inc/Module/Build/Sqitch.pm
@@ -17,7 +17,7 @@ __PACKAGE__->add_property($_) for qw(etcdir installed_etcdir);
 __PACKAGE__->add_property(with => []);
 
 # Set dual_life to true to force dual-life modules such as Pod::Simple to be
-# incliuded in the bundle directory.
+# included in the bundle directory.
 # --dual_life 1
 __PACKAGE__->add_property(dual_life => 0);
 
diff --git a/lib/App/Sqitch/Engine/Upgrade/firebird-1.0.sql b/lib/App/Sqitch/Engine/Upgrade/firebird-1.0.sql
index d666c416..ad38c89b 100644
--- a/lib/App/Sqitch/Engine/Upgrade/firebird-1.0.sql
+++ b/lib/App/Sqitch/Engine/Upgrade/firebird-1.0.sql
@@ -14,7 +14,7 @@ COMMENT ON COLUMN releases.installer_name  IS 'Name of the user who installed th
 COMMENT ON COLUMN releases.installer_email IS 'Email address of the user who installed the registry release.';
 
 -- Add the script_hash column to the changes table.
-ALTER TABLE changes ADD script_hash VARCHAR(40) UNIQUE;
+ALTER TABLE changes ADD script_hash VARCHAR(40) CHARACTER SET ASCII UNIQUE;
 COMMIT;
 UPDATE changes SET script_hash = change_id;
 COMMENT ON COLUMN changes.script_hash IS 'Deploy script SHA-1 hash.';
diff --git a/lib/App/Sqitch/Engine/Upgrade/mysql-1.0.sql b/lib/App/Sqitch/Engine/Upgrade/mysql-1.0.sql
index ac88c549..4549bcda 100644
--- a/lib/App/Sqitch/Engine/Upgrade/mysql-1.0.sql
+++ b/lib/App/Sqitch/Engine/Upgrade/mysql-1.0.sql
@@ -13,7 +13,7 @@ CREATE TABLE releases (
 ;
 
 -- Add the script_hash column to the changes table. Copy change_id for now.
-ALTER TABLE changes ADD COLUMN script_hash VARCHAR(40) NULL UNIQUE AFTER change_id;
+ALTER TABLE changes ADD COLUMN script_hash VARCHAR(40) CHARACTER SET ascii NULL UNIQUE AFTER change_id;
 UPDATE changes SET script_hash = change_id;
 
 -- Allow "merge" events.
diff --git a/lib/App/Sqitch/Engine/Upgrade/oracle-1.0.sql b/lib/App/Sqitch/Engine/Upgrade/oracle-1.0.sql
index d019d904..0e3754ee 100644
--- a/lib/App/Sqitch/Engine/Upgrade/oracle-1.0.sql
+++ b/lib/App/Sqitch/Engine/Upgrade/oracle-1.0.sql
@@ -12,7 +12,9 @@ COMMENT ON COLUMN &registry..releases.installer_name  IS 'Name of the user who i
 COMMENT ON COLUMN &registry..releases.installer_email IS 'Email address of the user who installed the registry release.';
 
 -- Add the script_hash column to the changes table. Copy change_id for now.
-ALTER TABLE &registry..changes ADD script_hash CHAR(40) NULL UNIQUE;
+-- https://docs.oracle.com/en/error-help/db/ora-43929/?r=23ai
+ALTER SESSION SET max_string_size=extended;
+ALTER TABLE &registry..changes ADD script_hash CHAR(40) COLLATE ASCII7 NULL UNIQUE;
 UPDATE &registry..changes SET script_hash = change_id;
 COMMENT ON COLUMN &registry..changes.script_hash IS 'Deploy script SHA-1 hash.';
 
diff --git a/lib/App/Sqitch/Engine/Upgrade/pg-1.0.sql b/lib/App/Sqitch/Engine/Upgrade/pg-1.0.sql
index 49f94176..e3c1c385 100644
--- a/lib/App/Sqitch/Engine/Upgrade/pg-1.0.sql
+++ b/lib/App/Sqitch/Engine/Upgrade/pg-1.0.sql
@@ -16,7 +16,7 @@ COMMENT ON COLUMN :"registry".releases.installer_name  IS 'Name of the user who
 COMMENT ON COLUMN :"registry".releases.installer_email IS 'Email address of the user who installed the registry release.';
 
 -- Add the script_hash column to the changes table. Copy change_id for now.
-ALTER TABLE :"registry".changes ADD COLUMN script_hash TEXT NULL UNIQUE;
+ALTER TABLE :"registry".changes ADD COLUMN script_hash TEXT COLLATE "C" NULL UNIQUE;
 UPDATE :"registry".changes SET script_hash = change_id;
 COMMENT ON COLUMN :"registry".changes.script_hash IS 'Deploy script SHA-1 hash.';
 
diff --git a/lib/App/Sqitch/Engine/cockroach.sql b/lib/App/Sqitch/Engine/cockroach.sql
index 717bdd26..9949ccca 100644
--- a/lib/App/Sqitch/Engine/cockroach.sql
+++ b/lib/App/Sqitch/Engine/cockroach.sql
@@ -16,12 +16,14 @@ COMMENT ON COLUMN :"registry".releases.installed_at    IS 'Date the registry rel
 COMMENT ON COLUMN :"registry".releases.installer_name  IS 'Name of the user who installed the registry release.';
 COMMENT ON COLUMN :"registry".releases.installer_email IS 'Email address of the user who installed the registry release.';
 
+-- "C" collation bug: https://github.com/cockroachdb/cockroach/issues/108657
+
 CREATE TABLE :"registry".projects (
-    project         TEXT        PRIMARY KEY,
-    uri             TEXT            NULL UNIQUE,
-    created_at      TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
-    creator_name    TEXT        NOT NULL,
-    creator_email   TEXT        NOT NULL
+    project         TEXT             PRIMARY KEY,
+    uri             TEXT COLLATE "en-US-u-va-posix"     NULL UNIQUE,
+    created_at      TIMESTAMPTZ      NOT NULL DEFAULT clock_timestamp(),
+    creator_name    TEXT             NOT NULL,
+    creator_email   TEXT             NOT NULL
 );
 
 COMMENT ON TABLE  :"registry".projects                IS 'Sqitch projects deployed to this database.';
@@ -32,17 +34,17 @@ COMMENT ON COLUMN :"registry".projects.creator_name   IS 'Name of the user who a
 COMMENT ON COLUMN :"registry".projects.creator_email  IS 'Email address of the user who added the project.';
 
 CREATE TABLE :"registry".changes (
-    change_id       TEXT        PRIMARY KEY,
-    script_hash     TEXT            NULL,
-    change          TEXT        NOT NULL,
-    project         TEXT        NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
-    note            TEXT        NOT NULL DEFAULT '',
-    committed_at    TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
-    committer_name  TEXT        NOT NULL,
-    committer_email TEXT        NOT NULL,
-    planned_at      TIMESTAMPTZ NOT NULL,
-    planner_name    TEXT        NOT NULL,
-    planner_email   TEXT        NOT NULL,
+    change_id       TEXT COLLATE "en-US-u-va-posix" PRIMARY KEY,
+    script_hash     TEXT COLLATE "en-US-u-va-posix"     NULL,
+    change          TEXT             NOT NULL,
+    project         TEXT             NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
+    note            TEXT             NOT NULL DEFAULT '',
+    committed_at    TIMESTAMPTZ      NOT NULL DEFAULT clock_timestamp(),
+    committer_name  TEXT             NOT NULL,
+    committer_email TEXT             NOT NULL,
+    planned_at      TIMESTAMPTZ      NOT NULL,
+    planner_name    TEXT             NOT NULL,
+    planner_email   TEXT             NOT NULL,
     UNIQUE(project, script_hash)
 );
 
@@ -60,17 +62,17 @@ COMMENT ON COLUMN :"registry".changes.planner_name    IS 'Name of the user who p
 COMMENT ON COLUMN :"registry".changes.planner_email   IS 'Email address of the user who planned the change.';
 
 CREATE TABLE :"registry".tags (
-    tag_id          TEXT        PRIMARY KEY,
-    tag             TEXT        NOT NULL,
-    project         TEXT        NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
-    change_id       TEXT        NOT NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE,
-    note            TEXT        NOT NULL DEFAULT '',
-    committed_at    TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
-    committer_name  TEXT        NOT NULL,
-    committer_email TEXT        NOT NULL,
-    planned_at      TIMESTAMPTZ NOT NULL,
-    planner_name    TEXT        NOT NULL,
-    planner_email   TEXT        NOT NULL,
+    tag_id          TEXT COLLATE "en-US-u-va-posix" PRIMARY KEY,
+    tag             TEXT             NOT NULL,
+    project         TEXT             NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
+    change_id       TEXT COLLATE "en-US-u-va-posix" NOT NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE,
+    note            TEXT             NOT NULL DEFAULT '',
+    committed_at    TIMESTAMPTZ      NOT NULL DEFAULT clock_timestamp(),
+    committer_name  TEXT             NOT NULL,
+    committer_email TEXT             NOT NULL,
+    planned_at      TIMESTAMPTZ      NOT NULL,
+    planner_name    TEXT             NOT NULL,
+    planner_email   TEXT             NOT NULL,
     UNIQUE(project, tag)
 );
 
@@ -88,10 +90,10 @@ COMMENT ON COLUMN :"registry".tags.planner_name    IS 'Name of the user who plan
 COMMENT ON COLUMN :"registry".tags.planner_email   IS 'Email address of the user who planned the tag.';
 
 CREATE TABLE :"registry".dependencies (
-    change_id       TEXT        NOT NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE ON DELETE CASCADE,
-    type            TEXT        NOT NULL,
-    dependency      TEXT        NOT NULL,
-    dependency_id   TEXT            NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE CONSTRAINT dependencies_check CHECK (
+    change_id       TEXT COLLATE "en-US-u-va-posix" NOT NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE ON DELETE CASCADE,
+    type            TEXT COLLATE "en-US-u-va-posix" NOT NULL,
+    dependency      TEXT             NOT NULL,
+    dependency_id   TEXT COLLATE "en-US-u-va-posix" NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE CONSTRAINT dependencies_check CHECK (
             (type = 'require'  AND dependency_id IS NOT NULL)
          OR (type = 'conflict' AND dependency_id IS NULL)
     ),
@@ -105,22 +107,22 @@ COMMENT ON COLUMN :"registry".dependencies.dependency    IS 'Dependency name.';
 COMMENT ON COLUMN :"registry".dependencies.dependency_id IS 'Change ID the dependency resolves to.';
 
 CREATE TABLE :"registry".events (
-    event           TEXT        NOT NULL CONSTRAINT events_event_check CHECK (
+    event           TEXT COLLATE "en-US-u-va-posix" NOT NULL CONSTRAINT events_event_check CHECK (
         event IN ('deploy', 'revert', 'fail', 'merge')
     ),
-    change_id       TEXT        NOT NULL,
-    change          TEXT        NOT NULL,
-    project         TEXT        NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
-    note            TEXT        NOT NULL DEFAULT '',
-    requires        TEXT[]      NOT NULL DEFAULT '{}',
-    conflicts       TEXT[]      NOT NULL DEFAULT '{}',
-    tags            TEXT[]      NOT NULL DEFAULT '{}',
-    committed_at    TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
-    committer_name  TEXT        NOT NULL,
-    committer_email TEXT        NOT NULL,
-    planned_at      TIMESTAMPTZ NOT NULL,
-    planner_name    TEXT        NOT NULL,
-    planner_email   TEXT        NOT NULL,
+    change_id       TEXT COLLATE "en-US-u-va-posix" NOT NULL,
+    change          TEXT             NOT NULL,
+    project         TEXT             NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
+    note            TEXT             NOT NULL DEFAULT '',
+    requires        TEXT[]           NOT NULL DEFAULT '{}',
+    conflicts       TEXT[]           NOT NULL DEFAULT '{}',
+    tags            TEXT[]           NOT NULL DEFAULT '{}',
+    committed_at    TIMESTAMPTZ      NOT NULL DEFAULT clock_timestamp(),
+    committer_name  TEXT             NOT NULL,
+    committer_email TEXT             NOT NULL,
+    planned_at      TIMESTAMPTZ      NOT NULL,
+    planner_name    TEXT             NOT NULL,
+    planner_email   TEXT             NOT NULL,
     PRIMARY KEY (change_id, committed_at)
 );
 
diff --git a/lib/App/Sqitch/Engine/exasol.sql b/lib/App/Sqitch/Engine/exasol.sql
index d7731ad5..0fa1351a 100644
--- a/lib/App/Sqitch/Engine/exasol.sql
+++ b/lib/App/Sqitch/Engine/exasol.sql
@@ -16,11 +16,11 @@ COMMENT ON COLUMN &registry..releases.installer_name  IS 'Name of the user who i
 COMMENT ON COLUMN &registry..releases.installer_email IS 'Email address of the user who installed the registry release.';
 
 CREATE TABLE &registry..projects (
-    project         VARCHAR2(512 CHAR)       PRIMARY KEY,
-    uri             VARCHAR2(512 CHAR)       NULL, -- UNIQUE should also be used here, but not supported in EXASOL
-    created_at      TIMESTAMP WITH LOCAL TIME ZONE DEFAULT current_timestamp NOT NULL,
-    creator_name    VARCHAR2(512 CHAR)       NOT NULL,
-    creator_email   VARCHAR2(512 CHAR)       NOT NULL
+    project         VARCHAR2(512 CHAR)                     PRIMARY KEY,
+    uri             VARCHAR2(512 CHAR) CHARACTER SET ASCII     NULL, -- UNIQUE should also be used here, but not supported in EXASOL
+    created_at      TIMESTAMP WITH LOCAL TIME ZONE         DEFAULT current_timestamp NOT NULL,
+    creator_name    VARCHAR2(512 CHAR)                     NOT NULL,
+    creator_email   VARCHAR2(512 CHAR)                     NOT NULL
 );
 
 COMMENT ON TABLE  &registry..projects                IS 'Sqitch projects deployed to this database.';
@@ -31,17 +31,17 @@ COMMENT ON COLUMN &registry..projects.creator_name   IS 'Name of the user who ad
 COMMENT ON COLUMN &registry..projects.creator_email  IS 'Email address of the user who added the project.';
 
 CREATE TABLE &registry..changes (
-    change_id       CHAR(40)                 PRIMARY KEY,
-    script_hash     CHAR(40)                     NULL,
-    change          VARCHAR2(512 CHAR)       NOT NULL,
-    project         VARCHAR2(512 CHAR)       NOT NULL REFERENCES &registry..projects(project),
-    note            VARCHAR2(4000 CHAR)      DEFAULT '',
+    change_id       CHAR(40) CHARACTER SET ASCII  PRIMARY KEY,
+    script_hash     CHAR(40) CHARACTER SET ASCII       NULL,
+    change          VARCHAR2(512 CHAR)             NOT NULL,
+    project         VARCHAR2(512 CHAR)             NOT NULL REFERENCES &registry..projects(project),
+    note            VARCHAR2(4000 CHAR)            DEFAULT '',
     committed_at    TIMESTAMP WITH LOCAL TIME ZONE DEFAULT current_timestamp NOT NULL,
-    committer_name  VARCHAR2(512 CHAR)       NOT NULL,
-    committer_email VARCHAR2(512 CHAR)       NOT NULL,
+    committer_name  VARCHAR2(512 CHAR)             NOT NULL,
+    committer_email VARCHAR2(512 CHAR)             NOT NULL,
     planned_at      TIMESTAMP WITH LOCAL TIME ZONE NOT NULL,
-    planner_name    VARCHAR2(512 CHAR)       NOT NULL,
-    planner_email   VARCHAR2(512 CHAR)       NOT NULL
+    planner_name    VARCHAR2(512 CHAR)             NOT NULL,
+    planner_email   VARCHAR2(512 CHAR)             NOT NULL
     -- UNIQUE(project, script_hash) -- not supported in EXASOL
 );
 
@@ -59,17 +59,17 @@ COMMENT ON COLUMN &registry..changes.planner_name    IS 'Name of the user who pl
 COMMENT ON COLUMN &registry..changes.planner_email   IS 'Email address of the user who planned the change.';
 
 CREATE TABLE &registry..tags (
-    tag_id          CHAR(40)                 PRIMARY KEY,
-    tag             VARCHAR2(512 CHAR)       NOT NULL,
-    project         VARCHAR2(512 CHAR)       NOT NULL REFERENCES &registry..projects(project),
-    change_id       CHAR(40)                 NOT NULL REFERENCES &registry..changes(change_id),
-    note            VARCHAR2(4000 CHAR)      DEFAULT '',
+    tag_id          CHAR(40) CHARACTER SET ASCII   PRIMARY KEY,
+    tag             VARCHAR2(512 CHAR)             NOT NULL,
+    project         VARCHAR2(512 CHAR)             NOT NULL REFERENCES &registry..projects(project),
+    change_id       CHAR(40) CHARACTER SET ASCII   NOT NULL REFERENCES &registry..changes(change_id),
+    note            VARCHAR2(4000 CHAR)            DEFAULT '',
     committed_at    TIMESTAMP WITH LOCAL TIME ZONE DEFAULT current_timestamp NOT NULL,
-    committer_name  VARCHAR2(512 CHAR)       NOT NULL,
-    committer_email VARCHAR2(512 CHAR)       NOT NULL,
+    committer_name  VARCHAR2(512 CHAR)             NOT NULL,
+    committer_email VARCHAR2(512 CHAR)             NOT NULL,
     planned_at      TIMESTAMP WITH LOCAL TIME ZONE NOT NULL,
-    planner_name    VARCHAR2(512 CHAR)       NOT NULL,
-    planner_email   VARCHAR2(512 CHAR)       NOT NULL
+    planner_name    VARCHAR2(512 CHAR)             NOT NULL,
+    planner_email   VARCHAR2(512 CHAR)             NOT NULL
     -- UNIQUE(project, tag)
 );
 
@@ -87,10 +87,10 @@ COMMENT ON COLUMN &registry..tags.planner_name    IS 'Name of the user who plane
 COMMENT ON COLUMN &registry..tags.planner_email   IS 'Email address of the user who planned the tag.';
 
 CREATE TABLE &registry..dependencies (
-    change_id       CHAR(40)                 NOT NULL REFERENCES &registry..changes(change_id), -- ON DELETE CASCADE,
-    type            VARCHAR2(8)              NOT NULL,
-    dependency      VARCHAR2(1024 CHAR)      NOT NULL,
-    dependency_id   CHAR(40)                     NULL REFERENCES &registry..changes(change_id),
+    change_id       CHAR(40)    CHARACTER SET ASCII NOT NULL REFERENCES &registry..changes(change_id), -- ON DELETE CASCADE,
+    type            VARCHAR2(8) CHARACTER SET ASCII NOT NULL,
+    dependency      VARCHAR2(1024 CHAR)             NOT NULL,
+    dependency_id   CHAR(40)    CHARACTER SET ASCII     NULL REFERENCES &registry..changes(change_id),
     -- CONSTRAINT dependencies_check CHECK (
     --         (type = 'require'  AND dependency_id IS NOT NULL)
     --      OR (type = 'conflict' AND dependency_id IS NULL)
@@ -105,20 +105,20 @@ COMMENT ON COLUMN &registry..dependencies.dependency    IS 'Dependency name.';
 COMMENT ON COLUMN &registry..dependencies.dependency_id IS 'Change ID the dependency resolves to.';
 
 CREATE TABLE &registry..events (
-    event           VARCHAR2(6)                   NOT NULL,
-    change_id       CHAR(40)                      NOT NULL,
-    change          VARCHAR2(512 CHAR)            NOT NULL,
-    project         VARCHAR2(512 CHAR)            NOT NULL REFERENCES &registry..projects(project),
-    note            VARCHAR2(4000 CHAR)           DEFAULT '',
-    requires        VARCHAR2(4000 CHAR)           DEFAULT '' NOT NULL,
-    conflicts       VARCHAR2(4000 CHAR)           DEFAULT '' NOT NULL,
-    tags            VARCHAR2(4000 CHAR)           DEFAULT '' NOT NULL,
-    committed_at    TIMESTAMP WITH LOCAL TIME ZONE      DEFAULT current_timestamp NOT NULL,
-    committer_name  VARCHAR2(512 CHAR)            NOT NULL,
-    committer_email VARCHAR2(512 CHAR)            NOT NULL,
-    planned_at      TIMESTAMP WITH LOCAL TIME ZONE      NOT NULL,
-    planner_name    VARCHAR2(512 CHAR)            NOT NULL,
-    planner_email   VARCHAR2(512 CHAR)            NOT NULL
+    event           VARCHAR2(6) CHARACTER SET ASCII NOT NULL,
+    change_id       CHAR(40)    CHARACTER SET ASCII NOT NULL,
+    change          VARCHAR2(512 CHAR)              NOT NULL,
+    project         VARCHAR2(512 CHAR)              NOT NULL REFERENCES &registry..projects(project),
+    note            VARCHAR2(4000 CHAR)             DEFAULT '',
+    requires        VARCHAR2(4000 CHAR)             DEFAULT '' NOT NULL,
+    conflicts       VARCHAR2(4000 CHAR)             DEFAULT '' NOT NULL,
+    tags            VARCHAR2(4000 CHAR)             DEFAULT '' NOT NULL,
+    committed_at    TIMESTAMP WITH LOCAL TIME ZONE  DEFAULT current_timestamp NOT NULL,
+    committer_name  VARCHAR2(512 CHAR)              NOT NULL,
+    committer_email VARCHAR2(512 CHAR)              NOT NULL,
+    planned_at      TIMESTAMP WITH LOCAL TIME ZONE  NOT NULL,
+    planner_name    VARCHAR2(512 CHAR)              NOT NULL,
+    planner_email   VARCHAR2(512 CHAR)              NOT NULL
 );
 
 -- CREATE INDEX &registry..events_pkey ON &registry..events(change_id, committed_at);
diff --git a/lib/App/Sqitch/Engine/firebird.sql b/lib/App/Sqitch/Engine/firebird.sql
index 5757c172..3cf75f7f 100644
--- a/lib/App/Sqitch/Engine/firebird.sql
+++ b/lib/App/Sqitch/Engine/firebird.sql
@@ -26,7 +26,7 @@ COMMENT ON COLUMN releases.installer_email IS 'Email address of the user who ins
 
 CREATE TABLE projects (
     project         VARCHAR(255)  NOT NULL PRIMARY KEY,
-    uri             VARCHAR(255)  UNIQUE,
+    uri             VARCHAR(255) CHARACTER SET ASCII UNIQUE,
     created_at      TIMESTAMP     DEFAULT CURRENT_TIMESTAMP NOT NULL,
     creator_name    VARCHAR(255)  NOT NULL,
     creator_email   VARCHAR(255)  NOT NULL
@@ -42,8 +42,8 @@ COMMENT ON COLUMN projects.creator_email  IS 'Email address of the user who adde
 -- Table: changes
 
 CREATE TABLE changes (
-    change_id       VARCHAR(40)   NOT NULL PRIMARY KEY,
-    script_hash     VARCHAR(40),
+    change_id       VARCHAR(40) CHARACTER SET ASCII   NOT NULL PRIMARY KEY,
+    script_hash     VARCHAR(40) CHARACTER SET ASCII,
     change          VARCHAR(255)  NOT NULL,
     project         VARCHAR(255)  NOT NULL REFERENCES projects(project)
                                        ON UPDATE CASCADE,
@@ -73,11 +73,11 @@ COMMENT ON COLUMN changes.planner_email   IS 'Email address of the user who plan
 -- Table: tags
 
 CREATE TABLE tags (
-    tag_id          CHAR(40)      NOT NULL PRIMARY KEY,
+    tag_id          CHAR(40) CHARACTER SET ASCII NOT NULL PRIMARY KEY,
     tag             VARCHAR(250)  NOT NULL,
     project         VARCHAR(255)  NOT NULL REFERENCES projects(project)
                                         ON UPDATE CASCADE,
-    change_id       CHAR(40)      NOT NULL REFERENCES changes(change_id)
+    change_id       CHAR(40) CHARACTER SET ASCII NOT NULL REFERENCES changes(change_id)
                                         ON UPDATE CASCADE,
     note            BLOB SUB_TYPE TEXT DEFAULT '' NOT NULL,
     committed_at    TIMESTAMP     DEFAULT CURRENT_TIMESTAMP NOT NULL,
@@ -105,11 +105,11 @@ COMMENT ON COLUMN tags.planner_email   IS 'Email address of the user who planned
 -- Table: dependencies
 
 CREATE TABLE dependencies (
-    change_id       CHAR(40)      NOT NULL REFERENCES changes(change_id)
+    change_id       CHAR(40)   CHARACTER SET ASCII NOT NULL REFERENCES changes(change_id)
                                         ON UPDATE CASCADE ON DELETE CASCADE,
-    type            VARCHAR(8)    NOT NULL,
-    dependency      VARCHAR(512)  NOT NULL,
-    dependency_id   CHAR(40)      REFERENCES changes(change_id)
+    type            VARCHAR(8) CHARACTER SET ASCII NOT NULL,
+    dependency      VARCHAR(512)                   NOT NULL,
+    dependency_id   CHAR(40)   CHARACTER SET ASCII REFERENCES changes(change_id)
                                         ON UPDATE CASCADE CONSTRAINT dependencies_check CHECK (
            (type = 'require'  AND dependency_id IS NOT NULL)
         OR (type = 'conflict' AND dependency_id IS NULL)
@@ -126,11 +126,11 @@ COMMENT ON COLUMN dependencies.dependency_id IS 'Change ID the dependency resolv
 -- Table: events
 
 CREATE TABLE events (
-    event           VARCHAR(6)    NOT NULL
+    event           VARCHAR(6) CHARACTER SET ASCII NOT NULL
     CONSTRAINT events_event_check CHECK (
         event IN ('deploy', 'revert', 'fail', 'merge')
     ),
-    change_id       CHAR(40)      NOT NULL,
+    change_id       CHAR(40) CHARACTER SET ASCII NOT NULL,
     change          VARCHAR(512)  NOT NULL,
     project         VARCHAR(255)  NOT NULL REFERENCES projects(project)
                                         ON UPDATE CASCADE,
diff --git a/lib/App/Sqitch/Engine/mysql.sql b/lib/App/Sqitch/Engine/mysql.sql
index fea4a275..e93ae0f2 100644
--- a/lib/App/Sqitch/Engine/mysql.sql
+++ b/lib/App/Sqitch/Engine/mysql.sql
@@ -19,7 +19,7 @@ CREATE TABLE releases (
 CREATE TABLE projects (
     project         VARCHAR(255) PRIMARY KEY
                     COMMENT 'Unique Name of a project.',
-    uri             VARCHAR(255) NULL UNIQUE
+    uri             VARCHAR(255) CHARACTER SET ascii NULL UNIQUE
                     COMMENT 'Optional project URI',
     created_at      DATETIME(6)  NOT NULL
                     COMMENT 'Date the project was added to the database.',
@@ -33,9 +33,9 @@ CREATE TABLE projects (
 ;
 
 CREATE TABLE changes (
-    change_id       VARCHAR(40)  PRIMARY KEY
+    change_id       VARCHAR(40) CHARACTER SET ascii PRIMARY KEY
                     COMMENT 'Change primary key.',
-    script_hash     VARCHAR(40)      NULL
+    script_hash     VARCHAR(40) CHARACTER SET ascii NULL
                     COMMENT 'Deploy script SHA-1 hash.',
     "change"        VARCHAR(255) NOT NULL
                     COMMENT 'Name of a deployed change.',
@@ -63,14 +63,14 @@ CREATE TABLE changes (
 ;
 
 CREATE TABLE tags (
-    tag_id          VARCHAR(40)  PRIMARY KEY
+    tag_id          VARCHAR(40) CHARACTER SET ascii PRIMARY KEY
                     COMMENT 'Tag primary key.',
     tag             VARCHAR(255) NOT NULL
                     COMMENT 'Project-unique tag name.',
     project         VARCHAR(255) NOT NULL
                     COMMENT 'Name of the Sqitch project to which the tag belongs.'
                     REFERENCES projects(project) ON UPDATE CASCADE,
-    change_id       VARCHAR(40)  NOT NULL
+    change_id       VARCHAR(40) CHARACTER SET ascii NOT NULL
                     COMMENT 'ID of last change deployed before the tag was applied.'
                     REFERENCES changes(change_id) ON UPDATE CASCADE,
     note            VARCHAR(255) NOT NULL
@@ -94,14 +94,14 @@ CREATE TABLE tags (
 ;
 
 CREATE TABLE dependencies (
-    change_id       VARCHAR(40)  NOT NULL
+    change_id       VARCHAR(40) CHARACTER SET ascii NOT NULL
                     COMMENT 'ID of the depending change.'
                     REFERENCES changes(change_id) ON UPDATE CASCADE ON DELETE CASCADE,
-    type            VARCHAR(8)   NOT NULL
+    type            VARCHAR(8)  CHARACTER SET ascii NOT NULL
                     COMMENT 'Type of dependency.',
     dependency      VARCHAR(255) NOT NULL
                     COMMENT 'Dependency name.',
-    dependency_id   VARCHAR(40)      NULL
+    dependency_id   VARCHAR(40) CHARACTER SET ascii NULL
                     COMMENT 'Change ID the dependency resolves to.'
                     REFERENCES changes(change_id) ON UPDATE CASCADE,
     PRIMARY KEY (change_id, dependency)
@@ -111,9 +111,9 @@ CREATE TABLE dependencies (
 ;
 
 CREATE TABLE events (
-    event           ENUM ('deploy', 'fail', 'merge', 'revert') NOT NULL
+    event           ENUM ('deploy', 'fail', 'merge', 'revert') CHARACTER SET ascii NOT NULL
                     COMMENT 'Type of event.',
-    change_id       VARCHAR(40)  NOT NULL
+    change_id       VARCHAR(40) CHARACTER SET ascii NOT NULL
                     COMMENT 'Change ID.',
     "change"        VARCHAR(255) NOT NULL
                     COMMENT 'Change name.',
diff --git a/lib/App/Sqitch/Engine/oracle.sql b/lib/App/Sqitch/Engine/oracle.sql
index 2c3d2cf6..66c63070 100644
--- a/lib/App/Sqitch/Engine/oracle.sql
+++ b/lib/App/Sqitch/Engine/oracle.sql
@@ -1,3 +1,6 @@
+-- https://docs.oracle.com/en/error-help/db/ora-43929/?r=23ai
+ALTER SESSION SET max_string_size=extended;
+
 CREATE TABLE &registry..releases (
     version           FLOAT                    PRIMARY KEY,
     installed_at      TIMESTAMP WITH TIME ZONE DEFAULT current_timestamp NOT NULL,
@@ -12,11 +15,11 @@ COMMENT ON COLUMN &registry..releases.installer_name  IS 'Name of the user who i
 COMMENT ON COLUMN &registry..releases.installer_email IS 'Email address of the user who installed the registry release.';
 
 CREATE TABLE &registry..projects (
-    project         VARCHAR2(512 CHAR)       PRIMARY KEY,
-    uri             VARCHAR2(512 CHAR)       NULL UNIQUE,
+    project         VARCHAR2(512 CHAR)                PRIMARY KEY,
+    uri             VARCHAR2(512 CHAR) COLLATE ASCII7     NULL UNIQUE,
     created_at      TIMESTAMP WITH TIME ZONE DEFAULT current_timestamp NOT NULL,
-    creator_name    VARCHAR2(512 CHAR)       NOT NULL,
-    creator_email   VARCHAR2(512 CHAR)       NOT NULL
+    creator_name    VARCHAR2(512 CHAR)                NOT NULL,
+    creator_email   VARCHAR2(512 CHAR)                NOT NULL
 );
 
 COMMENT ON TABLE  &registry..projects                IS 'Sqitch projects deployed to this database.';
@@ -27,8 +30,8 @@ COMMENT ON COLUMN &registry..projects.creator_name   IS 'Name of the user who ad
 COMMENT ON COLUMN &registry..projects.creator_email  IS 'Email address of the user who added the project.';
 
 CREATE TABLE &registry..changes (
-    change_id       CHAR(40)                 PRIMARY KEY,
-    script_hash     CHAR(40)                     NULL,
+    change_id       CHAR(40) COLLATE ASCII7  PRIMARY KEY,
+    script_hash     CHAR(40) COLLATE ASCII7      NULL,
     change          VARCHAR2(512 CHAR)       NOT NULL,
     project         VARCHAR2(512 CHAR)       NOT NULL REFERENCES &registry..projects(project),
     note            VARCHAR2(4000 CHAR)      DEFAULT '',
@@ -55,10 +58,10 @@ COMMENT ON COLUMN &registry..changes.planner_name    IS 'Name of the user who pl
 COMMENT ON COLUMN &registry..changes.planner_email   IS 'Email address of the user who planned the change.';
 
 CREATE TABLE &registry..tags (
-    tag_id          CHAR(40)                 PRIMARY KEY,
+    tag_id          CHAR(40) COLLATE ASCII7  PRIMARY KEY,
     tag             VARCHAR2(512 CHAR)       NOT NULL,
     project         VARCHAR2(512 CHAR)       NOT NULL REFERENCES &registry..projects(project),
-    change_id       CHAR(40)                 NOT NULL REFERENCES &registry..changes(change_id),
+    change_id       CHAR(40) COLLATE ASCII7  NOT NULL REFERENCES &registry..changes(change_id),
     note            VARCHAR2(4000 CHAR)      DEFAULT '',
     committed_at    TIMESTAMP WITH TIME ZONE DEFAULT current_timestamp NOT NULL,
     committer_name  VARCHAR2(512 CHAR)       NOT NULL,
@@ -83,10 +86,10 @@ COMMENT ON COLUMN &registry..tags.planner_name    IS 'Name of the user who plane
 COMMENT ON COLUMN &registry..tags.planner_email   IS 'Email address of the user who planned the tag.';
 
 CREATE TABLE &registry..dependencies (
-    change_id       CHAR(40)                 NOT NULL REFERENCES &registry..changes(change_id) ON DELETE CASCADE,
-    type            VARCHAR2(8)              NOT NULL,
-    dependency      VARCHAR2(1024 CHAR)      NOT NULL,
-    dependency_id   CHAR(40)                     NULL REFERENCES &registry..changes(change_id),
+    change_id       CHAR(40) COLLATE ASCII7    NOT NULL REFERENCES &registry..changes(change_id) ON DELETE CASCADE,
+    type            VARCHAR2(8) COLLATE ASCII7 NOT NULL,
+    dependency      VARCHAR2(1024 CHAR)        NOT NULL,
+    dependency_id   CHAR(40) COLLATE ASCII7        NULL REFERENCES &registry..changes(change_id),
     CONSTRAINT dependencies_check CHECK (
             (type = 'require'  AND dependency_id IS NOT NULL)
          OR (type = 'conflict' AND dependency_id IS NULL)
@@ -104,11 +107,11 @@ CREATE TYPE &registry..sqitch_array AS varray(1024) OF VARCHAR2(512);
 /
 
 CREATE TABLE &registry..events (
-    event           VARCHAR2(6)                   NOT NULL
+    event           VARCHAR2(6) COLLATE ASCII7    NOT NULL
     CONSTRAINT events_event_check CHECK (
         event IN ('deploy', 'revert', 'fail', 'merge')
     ),
-    change_id       CHAR(40)                      NOT NULL,
+    change_id       CHAR(40) COLLATE ASCII7       NOT NULL,
     change          VARCHAR2(512 CHAR)            NOT NULL,
     project         VARCHAR2(512 CHAR)            NOT NULL REFERENCES &registry..projects(project),
     note            VARCHAR2(4000 CHAR)           DEFAULT '',
diff --git a/lib/App/Sqitch/Engine/pg.pm b/lib/App/Sqitch/Engine/pg.pm
index aa392564..897a516e 100644
--- a/lib/App/Sqitch/Engine/pg.pm
+++ b/lib/App/Sqitch/Engine/pg.pm
@@ -221,6 +221,10 @@ sub _run_registry_file {
     # Fetch the client version. 8.4 == 80400
     my $version =  $self->_probe('-c', 'SHOW server_version_num');
     my $psql_maj = $self->_psql_major_version;
+    my $yb_version = $self->_provider eq 'postgres' ? 9999 : do {
+        my ($v) = $self->_probe('-c', 'SHOW server_version') =~ /-YB-(\d+\.\d+)/;
+        $v;
+    };
 
     # Is this XC?
     my $opts =  $self->_probe('-c', q{
@@ -231,14 +235,18 @@ sub _run_registry_file {
            AND proname = 'pgxc_version';
     }) ? ' DISTRIBUTE BY REPLICATION' : '';
 
-    if ($version < 90300 || $psql_maj < 9) {
+    if ($version < 90300 || $psql_maj < 9 || $yb_version < 2.9) {
         # Need to transform the SQL and write it to a temp file.
         my $sql = scalar $file->slurp;
 
         # No CREATE SCHEMA IF NOT EXISTS syntax prior to 9.3.
         $sql =~ s/SCHEMA IF NOT EXISTS/SCHEMA/ if $version < 90300;
+
+        # No COLLATE expression prior to 9.1 or Yugabyte 2.9.
+        $sql =~ s/COLLATE "POSIX"//g if $version < 90100 || $yb_version < 2.9;
+
         if ($psql_maj < 9) {
-            # Also no :"registry" variable syntax prior to psql 9.0.s
+            # No :"registry" variable syntax prior to psql 9.0.s
             ($schema) = $self->dbh->selectrow_array(
                 'SELECT quote_ident(?)', undef, $schema
             );
diff --git a/lib/App/Sqitch/Engine/pg.sql b/lib/App/Sqitch/Engine/pg.sql
index 87a0375a..7dd12ba1 100644
--- a/lib/App/Sqitch/Engine/pg.sql
+++ b/lib/App/Sqitch/Engine/pg.sql
@@ -10,7 +10,7 @@ CREATE TABLE :"registry".releases (
     installed_at    TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
     installer_name  TEXT        NOT NULL,
     installer_email TEXT        NOT NULL
-);
+):tableopts;
 
 COMMENT ON TABLE  :"registry".releases                 IS 'Sqitch registry releases.';
 COMMENT ON COLUMN :"registry".releases.version         IS 'Version of the Sqitch registry.';
@@ -19,11 +19,11 @@ COMMENT ON COLUMN :"registry".releases.installer_name  IS 'Name of the user who
 COMMENT ON COLUMN :"registry".releases.installer_email IS 'Email address of the user who installed the registry release.';
 
 CREATE TABLE :"registry".projects (
-    project         TEXT        PRIMARY KEY,
-    uri             TEXT            NULL UNIQUE,
-    created_at      TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
-    creator_name    TEXT        NOT NULL,
-    creator_email   TEXT        NOT NULL
+    project         TEXT             PRIMARY KEY,
+    uri             TEXT COLLATE "C"     NULL UNIQUE,
+    created_at      TIMESTAMPTZ      NOT NULL DEFAULT clock_timestamp(),
+    creator_name    TEXT             NOT NULL,
+    creator_email   TEXT             NOT NULL
 ):tableopts;
 
 COMMENT ON TABLE  :"registry".projects                IS 'Sqitch projects deployed to this database.';
@@ -34,17 +34,17 @@ COMMENT ON COLUMN :"registry".projects.creator_name   IS 'Name of the user who a
 COMMENT ON COLUMN :"registry".projects.creator_email  IS 'Email address of the user who added the project.';
 
 CREATE TABLE :"registry".changes (
-    change_id       TEXT        PRIMARY KEY,
-    script_hash     TEXT            NULL,
-    change          TEXT        NOT NULL,
-    project         TEXT        NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
-    note            TEXT        NOT NULL DEFAULT '',
-    committed_at    TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
-    committer_name  TEXT        NOT NULL,
-    committer_email TEXT        NOT NULL,
-    planned_at      TIMESTAMPTZ NOT NULL,
-    planner_name    TEXT        NOT NULL,
-    planner_email   TEXT        NOT NULL,
+    change_id       TEXT COLLATE "C" PRIMARY KEY,
+    script_hash     TEXT COLLATE "C"     NULL,
+    change          TEXT             NOT NULL,
+    project         TEXT             NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
+    note            TEXT             NOT NULL DEFAULT '',
+    committed_at    TIMESTAMPTZ      NOT NULL DEFAULT clock_timestamp(),
+    committer_name  TEXT             NOT NULL,
+    committer_email TEXT             NOT NULL,
+    planned_at      TIMESTAMPTZ      NOT NULL,
+    planner_name    TEXT             NOT NULL,
+    planner_email   TEXT             NOT NULL,
     UNIQUE(project, script_hash)
 ):tableopts;
 
@@ -62,17 +62,17 @@ COMMENT ON COLUMN :"registry".changes.planner_name    IS 'Name of the user who p
 COMMENT ON COLUMN :"registry".changes.planner_email   IS 'Email address of the user who planned the change.';
 
 CREATE TABLE :"registry".tags (
-    tag_id          TEXT        PRIMARY KEY,
-    tag             TEXT        NOT NULL,
-    project         TEXT        NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
-    change_id       TEXT        NOT NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE,
-    note            TEXT        NOT NULL DEFAULT '',
-    committed_at    TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
-    committer_name  TEXT        NOT NULL,
-    committer_email TEXT        NOT NULL,
-    planned_at      TIMESTAMPTZ NOT NULL,
-    planner_name    TEXT        NOT NULL,
-    planner_email   TEXT        NOT NULL,
+    tag_id          TEXT COLLATE "C" PRIMARY KEY,
+    tag             TEXT             NOT NULL,
+    project         TEXT             NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
+    change_id       TEXT COLLATE "C" NOT NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE,
+    note            TEXT             NOT NULL DEFAULT '',
+    committed_at    TIMESTAMPTZ      NOT NULL DEFAULT clock_timestamp(),
+    committer_name  TEXT             NOT NULL,
+    committer_email TEXT             NOT NULL,
+    planned_at      TIMESTAMPTZ      NOT NULL,
+    planner_name    TEXT             NOT NULL,
+    planner_email   TEXT             NOT NULL,
     UNIQUE(project, tag)
 ):tableopts;
 
@@ -90,10 +90,10 @@ COMMENT ON COLUMN :"registry".tags.planner_name    IS 'Name of the user who plan
 COMMENT ON COLUMN :"registry".tags.planner_email   IS 'Email address of the user who planned the tag.';
 
 CREATE TABLE :"registry".dependencies (
-    change_id       TEXT        NOT NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE ON DELETE CASCADE,
-    type            TEXT        NOT NULL,
-    dependency      TEXT        NOT NULL,
-    dependency_id   TEXT            NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE CONSTRAINT dependencies_check CHECK (
+    change_id       TEXT COLLATE "C" NOT NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE ON DELETE CASCADE,
+    type            TEXT COLLATE "C" NOT NULL,
+    dependency      TEXT             NOT NULL,
+    dependency_id   TEXT COLLATE "C"     NULL REFERENCES :"registry".changes(change_id) ON UPDATE CASCADE CONSTRAINT dependencies_check CHECK (
             (type = 'require'  AND dependency_id IS NOT NULL)
          OR (type = 'conflict' AND dependency_id IS NULL)
     ),
@@ -107,22 +107,22 @@ COMMENT ON COLUMN :"registry".dependencies.dependency    IS 'Dependency name.';
 COMMENT ON COLUMN :"registry".dependencies.dependency_id IS 'Change ID the dependency resolves to.';
 
 CREATE TABLE :"registry".events (
-    event           TEXT        NOT NULL CONSTRAINT events_event_check CHECK (
+    event           TEXT COLLATE "C" NOT NULL CONSTRAINT events_event_check CHECK (
         event IN ('deploy', 'revert', 'fail', 'merge')
     ),
-    change_id       TEXT        NOT NULL,
-    change          TEXT        NOT NULL,
-    project         TEXT        NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
-    note            TEXT        NOT NULL DEFAULT '',
-    requires        TEXT[]      NOT NULL DEFAULT '{}',
-    conflicts       TEXT[]      NOT NULL DEFAULT '{}',
-    tags            TEXT[]      NOT NULL DEFAULT '{}',
-    committed_at    TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
-    committer_name  TEXT        NOT NULL,
-    committer_email TEXT        NOT NULL,
-    planned_at      TIMESTAMPTZ NOT NULL,
-    planner_name    TEXT        NOT NULL,
-    planner_email   TEXT        NOT NULL,
+    change_id       TEXT COLLATE "C" NOT NULL,
+    change          TEXT             NOT NULL,
+    project         TEXT             NOT NULL REFERENCES :"registry".projects(project) ON UPDATE CASCADE,
+    note            TEXT             NOT NULL DEFAULT '',
+    requires        TEXT[]           NOT NULL DEFAULT '{}',
+    conflicts       TEXT[]           NOT NULL DEFAULT '{}',
+    tags            TEXT[]           NOT NULL DEFAULT '{}',
+    committed_at    TIMESTAMPTZ      NOT NULL DEFAULT clock_timestamp(),
+    committer_name  TEXT             NOT NULL,
+    committer_email TEXT             NOT NULL,
+    planned_at      TIMESTAMPTZ      NOT NULL,
+    planner_name    TEXT             NOT NULL,
+    planner_email   TEXT             NOT NULL,
     PRIMARY KEY (change_id, committed_at)
 ):tableopts;
 
diff --git a/lib/App/Sqitch/Engine/snowflake.sql b/lib/App/Sqitch/Engine/snowflake.sql
index 93b244e2..acd2b32c 100644
--- a/lib/App/Sqitch/Engine/snowflake.sql
+++ b/lib/App/Sqitch/Engine/snowflake.sql
@@ -15,12 +15,12 @@ COMMENT ON COLUMN &registry.releases.installed_at    IS 'Date the registry relea
 COMMENT ON COLUMN &registry.releases.installer_name  IS 'Name of the user who installed the registry release.';
 COMMENT ON COLUMN &registry.releases.installer_email IS 'Email address of the user who installed the registry release.';
 
-CREATE TABLE &registry.projects (
-    project         TEXT         PRIMARY KEY,
-    uri             TEXT             NULL UNIQUE,
-    created_at      TIMESTAMP_TZ NOT NULL DEFAULT current_timestamp,
-    creator_name    TEXT         NOT NULL,
-    creator_email   TEXT         NOT NULL
+CREATE TABLE projects (
+    project         TEXT                       PRIMARY KEY,
+    uri             TEXT COLLATE 'en_us_posix' NULL UNIQUE,
+    created_at      TIMESTAMP_TZ               NOT NULL DEFAULT current_timestamp,
+    creator_name    TEXT                       NOT NULL,
+    creator_email   TEXT                       NOT NULL
 );
 
 COMMENT ON TABLE  &registry.projects                IS 'Sqitch projects deployed to this database.';
@@ -31,17 +31,17 @@ COMMENT ON COLUMN &registry.projects.creator_name   IS 'Name of the user who add
 COMMENT ON COLUMN &registry.projects.creator_email  IS 'Email address of the user who added the project.';
 
 CREATE TABLE &registry.changes (
-    change_id       TEXT         PRIMARY KEY,
-    script_hash     TEXT             NULL,
-    change          TEXT         NOT NULL,
-    project         TEXT         NOT NULL REFERENCES &registry.projects(project) ON UPDATE CASCADE,
-    note            TEXT         NOT NULL DEFAULT '',
-    committed_at    TIMESTAMP_TZ NOT NULL DEFAULT current_timestamp,
-    committer_name  TEXT         NOT NULL,
-    committer_email TEXT         NOT NULL,
-    planned_at      TIMESTAMP_TZ NOT NULL,
-    planner_name    TEXT         NOT NULL,
-    planner_email   TEXT         NOT NULL,
+    change_id       TEXT COLLATE 'en_us_posix' PRIMARY KEY,
+    script_hash     TEXT COLLATE 'en_us_posix'     NULL,
+    change          TEXT                       NOT NULL,
+    project         TEXT                       NOT NULL REFERENCES &registry.projects(project) ON UPDATE CASCADE,
+    note            TEXT                       NOT NULL DEFAULT '',
+    committed_at    TIMESTAMP_TZ               NOT NULL DEFAULT current_timestamp,
+    committer_name  TEXT                       NOT NULL,
+    committer_email TEXT                       NOT NULL,
+    planned_at      TIMESTAMP_TZ               NOT NULL,
+    planner_name    TEXT                       NOT NULL,
+    planner_email   TEXT                       NOT NULL,
     UNIQUE(project, script_hash)
 );
 
@@ -59,17 +59,17 @@ COMMENT ON COLUMN &registry.changes.planner_name    IS 'Name of the user who pla
 COMMENT ON COLUMN &registry.changes.planner_email   IS 'Email address of the user who planned the change.';
 
 CREATE TABLE &registry.tags (
-    tag_id          TEXT        PRIMARY KEY,
-    tag             TEXT        NOT NULL,
-    project         TEXT        NOT NULL REFERENCES &registry.projects(project) ON UPDATE CASCADE,
-    change_id       TEXT        NOT NULL REFERENCES &registry.changes(change_id) ON UPDATE CASCADE,
-    note            TEXT        NOT NULL DEFAULT '',
-    committed_at    TIMESTAMPTZ NOT NULL DEFAULT current_timestamp,
-    committer_name  TEXT        NOT NULL,
-    committer_email TEXT        NOT NULL,
-    planned_at      TIMESTAMPTZ NOT NULL,
-    planner_name    TEXT        NOT NULL,
-    planner_email   TEXT        NOT NULL,
+    tag_id          TEXT COLLATE 'en_us_posix' PRIMARY KEY,
+    tag             TEXT                       NOT NULL,
+    project         TEXT                       NOT NULL REFERENCES &registry.projects(project) ON UPDATE CASCADE,
+    change_id       TEXT COLLATE 'en_us_posix' NOT NULL REFERENCES &registry.changes(change_id) ON UPDATE CASCADE,
+    note            TEXT                       NOT NULL DEFAULT '',
+    committed_at    TIMESTAMPTZ                NOT NULL DEFAULT current_timestamp,
+    committer_name  TEXT                       NOT NULL,
+    committer_email TEXT                       NOT NULL,
+    planned_at      TIMESTAMPTZ                NOT NULL,
+    planner_name    TEXT                       NOT NULL,
+    planner_email   TEXT                       NOT NULL,
     UNIQUE(project, tag)
 );
 
@@ -87,10 +87,10 @@ COMMENT ON COLUMN &registry.tags.planner_name    IS 'Name of the user who planed
 COMMENT ON COLUMN &registry.tags.planner_email   IS 'Email address of the user who planned the tag.';
 
 CREATE TABLE &registry.dependencies (
-    change_id       TEXT        NOT NULL REFERENCES &registry.changes(change_id) ON UPDATE CASCADE ON DELETE CASCADE,
-    type            TEXT        NOT NULL,
-    dependency      TEXT        NOT NULL,
-    dependency_id   TEXT            NULL REFERENCES &registry.changes(change_id) ON UPDATE CASCADE,
+    change_id       TEXT COLLATE 'en_us_posix' NOT NULL REFERENCES &registry.changes(change_id) ON UPDATE CASCADE ON DELETE CASCADE,
+    type            TEXT COLLATE 'en_us_posix' NOT NULL,
+    dependency      TEXT                       NOT NULL,
+    dependency_id   TEXT COLLATE 'en_us_posix'     NULL REFERENCES &registry.changes(change_id) ON UPDATE CASCADE,
     -- CONSTRAINT dependencies_check CHECK (
     --         (type = 'require'  AND dependency_id IS NOT NULL)
     --      OR (type = 'conflict' AND dependency_id IS NULL)
@@ -105,23 +105,23 @@ COMMENT ON COLUMN &registry.dependencies.dependency    IS 'Dependency name.';
 COMMENT ON COLUMN &registry.dependencies.dependency_id IS 'Change ID the dependency resolves to.';
 
 CREATE TABLE &registry.events (
-    event           TEXT        NOT NULL,
+    event           TEXT COLLATE 'en_us_posix' NOT NULL,
     -- CONSTRAINT events_event_check CHECK (
     --     event IN ('deploy', 'revert', 'fail', 'merge')
     -- ),
-    change_id       TEXT        NOT NULL,
-    change          TEXT        NOT NULL,
-    project         TEXT        NOT NULL REFERENCES &registry.projects(project) ON UPDATE CASCADE,
-    note            TEXT        NOT NULL DEFAULT '',
-    requires        TEXT        NOT NULL DEFAULT '',
-    conflicts       TEXT        NOT NULL DEFAULT '',
-    tags            TEXT        NOT NULL DEFAULT '',
-    committed_at    TIMESTAMPTZ NOT NULL DEFAULT current_timestamp,
-    committer_name  TEXT        NOT NULL,
-    committer_email TEXT        NOT NULL,
-    planned_at      TIMESTAMPTZ NOT NULL,
-    planner_name    TEXT        NOT NULL,
-    planner_email   TEXT        NOT NULL,
+    change_id       TEXT COLLATE 'en_us_posix' NOT NULL,
+    change          TEXT                       NOT NULL,
+    project         TEXT                       NOT NULL REFERENCES &registry.projects(project) ON UPDATE CASCADE,
+    note            TEXT                       NOT NULL DEFAULT '',
+    requires        TEXT                       NOT NULL DEFAULT '',
+    conflicts       TEXT                       NOT NULL DEFAULT '',
+    tags            TEXT                       NOT NULL DEFAULT '',
+    committed_at    TIMESTAMPTZ                NOT NULL DEFAULT current_timestamp,
+    committer_name  TEXT                       NOT NULL,
+    committer_email TEXT                       NOT NULL,
+    planned_at      TIMESTAMPTZ                NOT NULL,
+    planner_name    TEXT                       NOT NULL,
+    planner_email   TEXT                       NOT NULL,
     PRIMARY KEY (change_id, committed_at)
 );