Bug #57281 Default value for engine_condition_pushdown is wrong in documentation
Submitted: 6 Oct 2010 12:17 Modified: 15 Oct 2010 14:23
Reporter: Olav Sandstå Email Updates:
Status: Closed Impact on me:
Category:MySQL Server: Documentation Severity:S3 (Non-critical)
Version:5.5.7 OS:Any
Assigned to: Paul DuBois CPU Architecture:Any

[6 Oct 2010 12:17] Olav Sandstå
The documentation is unclear/wrong about what the default value for the engine-condition-pushdown variable is. 

The correct default value is: ON (in mysql-5.5).

This is mentioned the following places in the documentation:


5.1.4 Server System Variables

In the section for "engine_condition_pushdown" it says:

a. The default value:

      Default: ON    (correct)

b. The sentence:

      "By default, this variable is OFF  (0). Setting it to ON (1) enables pushdown"

   which is wrong. Suggest changing this to:

      "By default, this variable is ON (1). Setting it to OFF (0) disables pushdown"


* 7.13.3. Condition Pushdown Optimization

  In this section we say: 

    "Condition pushdown is disabled by default"

  we should say: 

    "Condition pushdown is enabled by default"

  or even better: "Engine condition pushdown is enabled by default"


I also suggest that the following sentences in section "Controlling Switchable Optimizations" being updated:

 * "The flag for ... condition pushdown was added in MySQL 5.5.3. " 

   ==> suggestion: add the word "engine"

 * "For information about ... condition pushdown"

   ==> suggestion: add the word "engine"

How to repeat:
See description.
[6 Oct 2010 13:12] MySQL Verification Team
Thank you for the bug report.
[15 Oct 2010 14:23] Paul DuBois
Thank you for your bug report. This issue has been addressed in the documentation. The updated documentation will appear on our website shortly, and will be included in the next release of the relevant products.

Looks like the default changed from OFF in 5.0 to ON in 5.1+ and this change was not propagated throughout newer manuals.