421513 - Implement lazy statement initialization

Status: RESOLVED WONTFIX

(Toolkit :: Storage, defect)

Description

[Ondrej Brablc]

It is preferable to prepare a statement once and execute many times. This can, however, lead to increased Ts time. As you can see in bug 364272, preparation of statements in nsNavHistory::Init accounts for 0.41% of the startup time. A simple solution for this problem would be to modify mozStorageStatement in such a way that the actual preparation will be done when necessary - before the first execution of the statement or before binding parameters.

This could break some existing code which is for example reading from non existent table and if this fails, it creates the table. So I guess that we should be explicit and have something like InitializeLazy and use it. The cons of this is that after check-in of this bug we will need additional effort to see Ts improvement.

Comment 1

[Shawn Wilsher :sdwilsh]

Attachment: v0.1

Work in progress.  This doesn't link, and I'm not immediately sure why.  I won't work on this until I get some other bugs fixed, so feel free to run with it.

Comment 2

[Shawn Wilsher :sdwilsh]

Talking with dietrich, previous test results showed that this didn't actually buy us anything.