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# sqlite
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Package sqlite is a cgo-free port of SQLite. Although you could see mattn's driver (`github.com/mattn/go-sqlite3`) in go.mod file, we import it for tests only.
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SQLite is an in-process implementation of a self-contained, serverless,
zero-configuration, transactional SQL database engine.
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## Thanks
This project is sponsored by Schleibinger Geräte Teubert u. Greim GmbH by
allowing one of the maintainers to work on it also in office hours.
## Installation
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$ go get modernc.org/sqlite
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## Documentation
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[pkg.go.dev/modernc.org/sqlite ](https://pkg.go.dev/modernc.org/sqlite )
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## Builders
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[modern-c.appspot.com/-/builder/?importpath=modernc.org%2fsqlite ](https://modern-c.appspot.com/-/builder/?importpath=modernc.org%2fsqlite )
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## Speedtest1
Numbers for the pure Go version were produced by
~/src/modernc.org/sqlite/speedtest1$ go build & & ./speedtest1
Numbers for the pure C version were produced by
~/src/modernc.org/sqlite/testdata/sqlite-src-3410200/test$ gcc speedtest1.c ../../sqlite-amalgamation-3410200/sqlite3.c -lpthread -ldl & & ./a.out
The results are from Go version 1.20.4 and GCC version 10.2.1 on a
Linux/amd64 machine, CPU: AMD Ryzen 9 3900X 12-Core Processor ×
RAM. Shown are the best of 3 runs.
Go C
-- Speedtest1 for SQLite 3.41.2 2023-03-22 11:56:21 0d1fc92f94cb6b76bffe3ec34d69 -- Speedtest1 for SQLite 3.41.2 2023-03-22 11:56:21 0d1fc92f94cb6b76bffe3ec34d69
100 - 50000 INSERTs into table with no index...................... 0.071s 100 - 50000 INSERTs into table with no index...................... 0.077s
110 - 50000 ordered INSERTS with one index/PK..................... 0.114s 110 - 50000 ordered INSERTS with one index/PK..................... 0.082s
120 - 50000 unordered INSERTS with one index/PK................... 0.137s 120 - 50000 unordered INSERTS with one index/PK................... 0.099s
130 - 25 SELECTS, numeric BETWEEN, unindexed...................... 0.083s 130 - 25 SELECTS, numeric BETWEEN, unindexed...................... 0.091s
140 - 10 SELECTS, LIKE, unindexed................................. 0.210s 140 - 10 SELECTS, LIKE, unindexed................................. 0.120s
142 - 10 SELECTS w/ORDER BY, unindexed............................ 0.276s 142 - 10 SELECTS w/ORDER BY, unindexed............................ 0.182s
145 - 10 SELECTS w/ORDER BY and LIMIT, unindexed.................. 0.183s 145 - 10 SELECTS w/ORDER BY and LIMIT, unindexed.................. 0.099s
150 - CREATE INDEX five times..................................... 0.172s 150 - CREATE INDEX five times..................................... 0.127s
160 - 10000 SELECTS, numeric BETWEEN, indexed..................... 0.080s 160 - 10000 SELECTS, numeric BETWEEN, indexed..................... 0.078s
161 - 10000 SELECTS, numeric BETWEEN, PK.......................... 0.080s 161 - 10000 SELECTS, numeric BETWEEN, PK.......................... 0.078s
170 - 10000 SELECTS, text BETWEEN, indexed........................ 0.187s 170 - 10000 SELECTS, text BETWEEN, indexed........................ 0.169s
180 - 50000 INSERTS with three indexes............................ 0.196s 180 - 50000 INSERTS with three indexes............................ 0.154s
190 - DELETE and REFILL one table................................. 0.200s 190 - DELETE and REFILL one table................................. 0.155s
200 - VACUUM...................................................... 0.180s 200 - VACUUM...................................................... 0.142s
210 - ALTER TABLE ADD COLUMN, and query........................... 0.004s 210 - ALTER TABLE ADD COLUMN, and query........................... 0.005s
230 - 10000 UPDATES, numeric BETWEEN, indexed..................... 0.093s 230 - 10000 UPDATES, numeric BETWEEN, indexed..................... 0.080s
240 - 50000 UPDATES of individual rows............................ 0.153s 240 - 50000 UPDATES of individual rows............................ 0.137s
250 - One big UPDATE of the whole 50000-row table................. 0.024s 250 - One big UPDATE of the whole 50000-row table................. 0.019s
260 - Query added column after filling............................ 0.004s 260 - Query added column after filling............................ 0.005s
270 - 10000 DELETEs, numeric BETWEEN, indexed..................... 0.278s 270 - 10000 DELETEs, numeric BETWEEN, indexed..................... 0.263s
280 - 50000 DELETEs of individual rows............................ 0.188s 280 - 50000 DELETEs of individual rows............................ 0.180s
290 - Refill two 50000-row tables using REPLACE................... 0.411s 290 - Refill two 50000-row tables using REPLACE................... 0.359s
300 - Refill a 50000-row table using (b& 1)==(a& 1)................. 0.175s 300 - Refill a 50000-row table using (b& 1)==(a& 1)................. 0.151s
310 - 10000 four-ways joins....................................... 0.427s 310 - 10000 four-ways joins....................................... 0.365s
320 - subquery in result set...................................... 0.440s 320 - subquery in result set...................................... 0.521s
400 - 70000 REPLACE ops on an IPK................................. 0.125s 400 - 70000 REPLACE ops on an IPK................................. 0.106s
410 - 70000 SELECTS on an IPK..................................... 0.081s 410 - 70000 SELECTS on an IPK..................................... 0.078s
500 - 70000 REPLACE on TEXT PK.................................... 0.174s 500 - 70000 REPLACE on TEXT PK.................................... 0.116s
510 - 70000 SELECTS on a TEXT PK.................................. 0.153s 510 - 70000 SELECTS on a TEXT PK.................................. 0.117s
520 - 70000 SELECT DISTINCT....................................... 0.083s 520 - 70000 SELECT DISTINCT....................................... 0.067s
980 - PRAGMA integrity_check...................................... 0.436s 980 - PRAGMA integrity_check...................................... 0.377s
990 - ANALYZE..................................................... 0.107s 990 - ANALYZE..................................................... 0.038s
TOTAL....................................................... 5.525s TOTAL....................................................... 4.637s
This particular test executes 16.1% faster in the C version.
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## Troubleshooting
* Q: **How can I write to a database concurrently without getting the `database is locked` error (or `SQLITE_BUSY`)?**
* A: You can't. The C sqlite implementation does not allow concurrent writes, and this libary does not modify that behaviour. You can, however, use [DB.SetMaxOpenConns(1) ](https://pkg.go.dev/database/sql#DB.SetMaxOpenConns ) so that only 1 connection is ever used by the `DB` , allowing concurrent access to DB without making the writes concurrent. More information on issues [#65 ](https://gitlab.com/cznic/sqlite/-/issues/65 ) and [#106 ](https://gitlab.com/cznic/sqlite/-/issues/106 ).
