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Performance/Avoid SQLite In Your Next Firefox Feature: Difference between revisions
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Performance/Avoid SQLite In Your Next Firefox Feature (view source)
Revision as of 08:06, 8 April 2014
, 8 April 2014→Important Pragmas
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* Use a [https://www.sqlite.org/wal.html write-ahead log] for fewer fsyncs | * Use a [https://www.sqlite.org/wal.html write-ahead log] for fewer fsyncs | ||
** <code>PRAGMA journal_mode = WAL;</code> | ** <code>PRAGMA journal_mode = WAL;</code> | ||
** Though limit the size of the journal, by using a small autocheckpoint and a journal_size_limit about thrice that size | |||
*** <code>PRAGMA wal_autocheckpoint = 16; /* number of 32KiB pages in a 512KiB journal */</code> | |||
*** <code>PRAGMA journal_size_limit = 1536; /* 512KiB * 3 */</code> | |||
** If it's not possible to use WAL journaling, consider using a TRUNCATE journal | |||
* Set the DB cache size based on the device specs, and consider adjusting it dynamically based on memory pressure on mobile devices | * Set the DB cache size based on the device specs, and consider adjusting it dynamically based on memory pressure on mobile devices | ||
** <code>PRAGMA cache_size = X;</code> | ** <code>PRAGMA cache_size = X;</code> | ||
* For large DBs prone to fragmentation, pre-allocate a large empty DB initially by increasing the DB's growth increment | * For large DBs prone to fragmentation, pre-allocate a large empty DB initially by increasing the DB's growth increment | ||
** This can be done by calling Connection::SetGrowthIncrement() which changes the value of SQLite's <code>SQLITE_FCNTL_CHUNK_SIZE</code>. See {{bug|581606}} for reference. | ** This can be done by calling Connection::SetGrowthIncrement() which changes the value of SQLite's <code>SQLITE_FCNTL_CHUNK_SIZE</code>. See {{bug|581606}} for reference. | ||
* Use a memory temp store if the amount of data in memory entities is acceptable, otherwise temp data will be written to disk, causing unexpected I/O | |||
** <code>PRAGMA temp_store = MEMORY</code> | |||
=== More Tips === | === More Tips === | ||