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    <p>I know of no pretty graphical tools, but all of the information you seek is available from the <code>EXPLAIN</code> keyword.</p> <p>Consider this database:</p> <pre> sqlite> create table users (name, email); sqlite> create index user_names on users (name); </pre> <p>A query predicated on <code>email</code> will not use an index:</p> <pre> sqlite> explain select * from users where email='foo'; 0|Trace|0|0|0||00| 1|String8|0|1|0|foo|00| 2|Goto|0|13|0||00| 3|OpenRead|0|2|0|2|00| 4|Rewind|0|11|0||00| 5|Column|0|1|2||00| 6|Ne|1|10|2|collseq(BINARY)|6a| 7|Column|0|0|4||00| 8|Column|0|1|5||00| 9|ResultRow|4|2|0||00| 10|Next|0|5|0||01| 11|Close|0|0|0||00| 12|Halt|0|0|0||00| 13|Transaction|0|0|0||00| 14|VerifyCookie|0|5|0||00| 15|TableLock|0|2|0|users|00| 16|Goto|0|3|0||00| </pre> <p>Whereas a query predicated on name will use the <code>user_names</code> index:</p> <pre> sqlite> explain select * from users where name='foo'; 0|Trace|0|0|0||00| 1|String8|0|1|0|foo|00| 2|Goto|0|18|0||00| 3|OpenRead|0|2|0|2|00| 4|OpenRead|1|3|0|keyinfo(1,BINARY)|00| 5|IsNull|1|15|0||00| 6|Affinity|1|1|0|bb|00| 7|SeekGe|1|15|1|1|00| 8|IdxGE|1|15|1|1|01| 9|IdxRowid|1|2|0||00| 10|Seek|0|2|0||00| 11|Column|1|0|3||00| 12|Column|0|1|4||00| 13|ResultRow|3|2|0||00| 14|Next|1|8|0||00| 15|Close|0|0|0||00| 16|Close|1|0|0||00| 17|Halt|0|0|0||00| 18|Transaction|0|0|0||00| 19|VerifyCookie|0|5|0||00| 20|TableLock|0|2|0|users|00| 21|Goto|0|3|0||00| </pre> <p>Using <code>EXPLAIN</code> does require coming to grips with SQLite's virtual machine, VDBE:</p> <p><a href="http://www.sqlite.org/vdbe.html" rel="nofollow noreferrer">http://www.sqlite.org/vdbe.html</a></p> <p>But this is not as hard as it looks, and gives you the complete story about your query. </p>
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    1. POHow can I analyse a Sqlite query execution?
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    1. USDavid Crawshaw
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    1. POHow can I analyse a Sqlite query execution?
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    1. CO`EXPLAIN QUERY PLAN` will give info about index use without the VM instructions.
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    2. COYou can also improve the output format, if desired, by enabling the .explain option in the command line: ".explain ON|OFF Turn output mode suitable for EXPLAIN on or off."
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