APRIL - Complete Environment

Features

• Queries:
  • Spatial Join with predicate, available predicates:
    • intersect
    • disjoint
    • inside
    • contains
    • covered by
    • covers
    • meet
    • equal
    • find relation
• Rasterizer:
  • Full support to create APRIL and store on disk
• MBR Filter:
  • Two-Layer filter (D. Tsitsigkos et al.). APRIL filter is always after the MBR Filter in the pipeline
  • Optimized Two-Layer filter for "find relation" and "relate with predicate" queries
• APRIL Features
  • Partitioning mechanism [1,32] for better performance
  • SOON: compression
  • SOON: different granularity support

Build

In main directory, run source ./build.sh or

mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
cmake --build .
cd build
make

Inside build/ directory, the executable 'main' is program executable.

Run

• -c : creates the APRIL approximations for the input datasets.
• -R "keyword" : sets as the R input dataset, the dataset indicated by the keyword (see configuration files)
• -S "keyword" : sets as the S input dataset, the dataset indicated by the keyword (see configuration files)
• -q "query type" : sets the query type. Query types include:
• • disjoint : r and s are disjoint
• • intersect : r and s intersect
• • inside : r is inside s
• • contains : r contains s
• • covered_by : r is covered by s
• • covers : r covers s
• • meet : r and s meet (touch)
• • equal : r and s are geometrically equal
• • find_relation : detect all relations between r and s
• -s "setting" : sets the pipeline setting. Options include (ST2, ST3, OP2, OP3 and some development ones. For more, see topology relations paper.)
• -p "num" : sets "num" partitions for the APRIL approximation
• -e : evaluates the query 10 times and prints the average times
• -v "file" : export CSV with the results to "file". If file exists, then append the output

Configuration Files

config.ini

Includes the system parameters

datasets.ini

Includes the datasets parameters. To run on new datasets, first an entry must be added to the datasets.ini configuration file. Use a unique keyword for the section of the dataset's parameters. If using APRIL, make sure to specify '-c' in the first run to create APRIL for the dataset.

Example run:

./main -q <query_type> -s OP3 -R <my R dataset keyword> -S <my S dataset keyword>

WARNING: Datasets must have an offset map specified for faster refinement (TODO: add generation of offset map, currently unsupported)