Add elf_strings index for offset

* added recursive query for RPATH to README
* added index for elf_strings for offset column

README.md

@@ -310,8 +310,6 @@ polymorphic nature of the dynamic entries needed_.
 
 The below uses a file built with [NixOS](https://nixos.org) as they all have RUNPATH set.
 
-A recursive query can further be used to split the row into multiple rows. 
-
 ```console
 ❯ sqlelf /nix/store/gjr9ylm023rl9di484g1wxcd1jp84xxv-nix-2.8.1/bin/nix \
  --sql "SELECT elf_strings.path, elf_strings.value
@@ -328,6 +326,33 @@ WHERE elf_dynamic_entries.tag = 'RUNPATH';"
 └─────────────────────────────────────────────────┴───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
 ```
 
+A recursive query can further be used to split the row into multiple rows.
+
+```console
+❯ sqlelf /nix/store/gjr9ylm023rl9di484g1wxcd1jp84xxv-nix-2.8.1/bin/nix \
+--sql "WITH split(rpath, str) AS (
+    SELECT '', elf_strings.value||':' as rpath
+    FROM elf_dynamic_entries
+    INNER JOIN elf_strings ON elf_dynamic_entries.value = elf_strings.offset
+    WHERE elf_dynamic_entries.tag = 'RUNPATH'
+    UNION ALL SELECT
+    substr(str, 0, instr(str, ':')),
+    substr(str, instr(str, ':')+1)
+    FROM split WHERE str!=''
+) SELECT rpath FROM split WHERE rpath!='';"
+WARNING:root:SQLITE_LOG: automatic index on elf_strings(offset) (284) SQLITE_WARNING SQLITE_WARNING_AUTOINDEX
+┌────────────────────────────────────────────────────────────────────┐
+│                               rpath                                │
+│ /nix/store/gjr9ylm023rl9di484g1wxcd1jp84xxv-nix-2.8.1/lib          │
+│ /nix/store/pkxyfwarcq081rybpbnprjmnkiy1cz6g-libsodium-1.0.18/lib   │
+│ /nix/store/r6mrf9pz4dpax6rcszcmbyrpsk8j6saz-editline-1.17.1/lib    │
+│ /nix/store/ppm63lvkyfa58sgcnr2ddzh14dy1k9fn-boehm-gc-8.0.6/lib     │
+│ /nix/store/sgw2i15l01rwxzj62745h30bsjmh7wc1-lowdown-0.11.1-lib/lib │
+│ /nix/store/bvy2z17rzlvkx2sj7fy99ajm853yv898-glibc-2.34-210/lib     │
+│ /nix/store/gka59hya7l7qp26s0rydcgq8hj0d7v7k-gcc-11.3.0-lib/lib     │
+└────────────────────────────────────────────────────────────────────┘
+```
+
 </details>
 
 

sqlelf/cli.py

@@ -6,6 +6,7 @@
 from functools import reduce
 from typing import TextIO
 
+from sqlelf import elf
 from sqlelf import sql as api_sql
 
 
@@ -65,7 +66,9 @@ def start(args: list[str] = sys.argv[1:], stdin: TextIO = sys.stdin) -> None:
     if len(filenames) == 0:
         sys.exit("No valid ELF files were provided")
 
-    sql_engine = api_sql.make_sql_engine(filenames, recursive=program_args.recursive)
+    sql_engine = api_sql.make_sql_engine(
+        filenames, recursive=program_args.recursive, cache_flags=elf.CacheFlag.ALL()
+    )
     shell = sql_engine.shell(stdin=stdin)
 
     if program_args.sql and len(program_args.filenames) > 0:

sqlelf/elf.py

@@ -289,6 +289,11 @@ def strings_generator() -> Iterator[dict[str, Any]]:
         cache_flags,
     )
 
+    if CacheFlag.STRINGS in cache_flags:
+        connection.execute(
+            """CREATE INDEX elf_strings_offset_idx ON elf_strings (offset);"""
+        )
+
 
 def split_with_index(str: str, delimiter: str) -> list[tuple[int, str]]:
     """Split a string with the delimiter and return the index