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| author | Xavier Noria <fxn@hashref.com> | 2011-11-25 14:58:43 -0800 |
|---|---|---|
| committer | Xavier Noria <fxn@hashref.com> | 2011-11-25 14:58:43 -0800 |
| commit | b30b932447d3ae059c0dac2c5bf0a3a79e0fa54e (patch) | |
| tree | ee5000901fc37511568387797d19fd7e349ff076 | |
| parent | 1be9830d4d99e2bf56f1cadf74b843f22d66da35 (diff) | |
| download | rails-b30b932447d3ae059c0dac2c5bf0a3a79e0fa54e.tar.gz rails-b30b932447d3ae059c0dac2c5bf0a3a79e0fa54e.tar.bz2 rails-b30b932447d3ae059c0dac2c5bf0a3a79e0fa54e.zip | |
finders guide: adds some pointers to help users interpret the output of EXPLAIN
| -rw-r--r-- | railties/guides/source/active_record_querying.textile | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/railties/guides/source/active_record_querying.textile b/railties/guides/source/active_record_querying.textile index 0f1f6eba4c..c4724f182e 100644 --- a/railties/guides/source/active_record_querying.textile +++ b/railties/guides/source/active_record_querying.textile @@ -1344,3 +1344,14 @@ EXPLAIN for: SELECT `posts`.* FROM `posts` WHERE `posts`.`user_id` IN (1) </plain> under MySQL. + +h4. Interpreting EXPLAIN + +Interpretation of the output of EXPLAIN is beyond the scope of this guide. The +following pointers may be helpful: + +* SQLite3: "EXPLAIN QUERY PLAN":http://www.sqlite.org/eqp.html + +* MySQL: "EXPLAIN Output Format":http://dev.mysql.com/doc/refman/5.6/en/explain-output.html + +* PostgreSQL: "Using EXPLAIN":http://www.postgresql.org/docs/current/static/using-explain.html |