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author | Jeremy Cole <jeremy@jcole.us> | 2012-07-13 09:42:48 -0700 |
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committer | Jeremy Cole <jeremy@jcole.us> | 2012-07-13 09:42:48 -0700 |
commit | e4ef90a9817fe0b6bb6cceaf9876c59e60eef7ac (patch) | |
tree | eeb5cf4391e993ab8dc9af67c16dbe0db78f1222 /activerecord/test/cases/explain_subscriber_test.rb | |
parent | e72d8768878efd13b817ad91a12f872f53efd809 (diff) | |
download | rails-e4ef90a9817fe0b6bb6cceaf9876c59e60eef7ac.tar.gz rails-e4ef90a9817fe0b6bb6cceaf9876c59e60eef7ac.tar.bz2 rails-e4ef90a9817fe0b6bb6cceaf9876c59e60eef7ac.zip |
Only use prepared statements when bind variables are present
Prepared statements (prepare/execute/close) were being used unnecessarily
when no bind variables were present, and disabling prepared statement using
prepared_statements:false was principally broken. While bind variables were
correctly substituted with prepared_statements:false, the prepared statement
interface was still used, costing an extra two round trips per query.
In addition to making this behavioral change, I also cleaned up the internals
of exec_stmt and exec_without_stmt so that they behave the same (calling log
and constructing the ActiveRecord::Result in the same way).
Moving the check for binds.empty? to exec_query also will mean that several
code paths explicitly calling exec_without_stmt could be cleaned up to once
again call exec_query instead. I have also left the check for binds.empty? in
exec_stmt, since it is not a private method and could be called directly with
an empty binds array. For the sake of clarity in this patch, I have not made
those changes.
= The previous behavior =
When issuing a Foo.find(1) with prepared_statements:true, the bind variable
is present in the prepared query, and execute shows a value passed:
Connect root@localhost on rails_test
Query SET SQL_AUTO_IS_NULL=0
Statistics
Query SHOW FULL FIELDS FROM `foos`
Query SHOW TABLES LIKE 'foos'
Query SHOW CREATE TABLE `foos`
Prepare SELECT `foos`.* FROM `foos` WHERE `foos`.`id` = ? LIMIT 1
Execute SELECT `foos`.* FROM `foos` WHERE `foos`.`id` = 1 LIMIT 1
Close stmt
Quit
When issuing a Foo.find(1) with prepared_statements:false, the bind variable
has already been removed and substituted with the value, but the prepared
statement interface is used anyway:
Connect root@localhost on rails_test
Query SET SQL_AUTO_IS_NULL=0
Statistics
Query SHOW FULL FIELDS FROM `foos`
Query SHOW TABLES LIKE 'foos'
Query SHOW CREATE TABLE `foos`
Prepare SELECT `foos`.* FROM `foos` WHERE `foos`.`id` = 1 LIMIT 1
Execute SELECT `foos`.* FROM `foos` WHERE `foos`.`id` = 1 LIMIT 1
Close stmt
Quit
= With this patch applied =
When issuing a Foo.find(1) with prepared_statements:true, the bind variable
is present in the prepared query, and execute shows a value passed:
Connect root@localhost on rails_test
Query SET SQL_AUTO_IS_NULL=0
Statistics
Query SHOW FULL FIELDS FROM `foos`
Query SHOW TABLES LIKE 'foos'
Query SHOW CREATE TABLE `foos`
Prepare SELECT `foos`.* FROM `foos` WHERE `foos`.`id` = ? LIMIT 1
Execute SELECT `foos`.* FROM `foos` WHERE `foos`.`id` = 1 LIMIT 1
Close stmt
Quit
When issuing a Foo.find(1) with prepared_statements:false, the bind variable
has been removed and substituted with the value, and the query interface is
used instead of the prepared statement interface:
Connect root@localhost on rails_test
Query SET SQL_AUTO_IS_NULL=0
Statistics
Query SHOW FULL FIELDS FROM `foos`
Query SHOW TABLES LIKE 'foos'
Query SHOW CREATE TABLE `foos`
Query SELECT `foos`.* FROM `foos` WHERE `foos`.`id` = 1 LIMIT 1
Quit
Diffstat (limited to 'activerecord/test/cases/explain_subscriber_test.rb')
0 files changed, 0 insertions, 0 deletions