sqlite/test/json/README.md

The files in this subdirectory are used to help measure the performance of the SQLite JSON functions, especially in relation to handling large JSON inputs.

1.0 Prerequisites

• Standard SQLite build environment (SQLite source tree, compiler, make, etc.)

• Valgrind

• Fossil (only the "fossil xdiff" command is used by this procedure)

• tclsh

2.0 Setup

• Run: "tclsh json-generator.tcl | sqlite3 json100mb.db" to create the 100 megabyte test database. Do this so that the "json100mb.db" file lands in the directory from which you will run tests, not in the test/json subdirectory of the source tree.

• Make a copy of "json100mb.db" into "jsonb100mb.db" - change the prefix from "json" to "jsonb".

• Bring up jsonb100mb.db in the sqlite3 command-line shell. Convert all of the content into JSONB using a commands like this:

   UPDATE data1 SET x=jsonb(x);
   VACUUM;

• Build the baseline sqlite3.c file with sqlite3.h and shell.c.

   make clean sqlite3.c

• Run "sh json-speed-check.sh trunk". This creates the baseline profile in "jout-trunk.txt" for the preformance test using text JSON.

• Run "sh json-speed-check.sh trunk --jsonb". This creates the baseline profile in "joutb-trunk.txt" for the performance test for processing JSONB

• (Optional) Verify that the json100mb.db database really does contain approximately 100MB of JSON content by running:

   SELECT sum(length(x)) FROM data1;
   SELECT * FROM data1 WHERE NOT json_valid(x);

3.0 Testing

• Build the sqlite3.c (with sqlite3.h and shell.c) to be tested.

• Run "sh json-speed-check.sh x1". The profile output will appear in jout-x1.txt. Substitute any label you want in place of "x1".

• Run "sh json-speed-check.sh x1 --jsonb". The profile output will appear in joutb-x1.txt. Substitute any label you want in place of "x1".

• Run the script shown below in the CLI. Divide 2500 by the real elapse time from this test to get an estimate for number of MB/s that the JSON parser is able to process.

   .open json100mb.db
   .timer on
   WITH RECURSIVE c(n) AS (VALUES(1) UNION ALL SELECT n+1 FROM c WHERE n<25)
   SELECT sum(json_valid(x)) FROM c, data1;