issue-link js-issue-link" data-error-text="Failed to load title" data-id="666250326" data-permission-text="Title is private" data-url="https://github.com/zopefoundation/ZODB/issues/323" data-hovercard-type="pull_request" data-hovercard-url="/zopefoundation/ZODB/pull/323/hovercard" href="https://github.com/zopefoundation/ZODB/pull/323">zopefoundation/ZODB#323 On RelStorage loadBefore is currently implemented via 3 SQL queries: 1) check whether object record exists at all 2) retrieve object state 3) retrieve serial of next object revision Compared to that loadBeforeEx is implemented via only one SQL query "2" from the above - "retrieve object state". It is exactly the same query that loadBefore uses and after the patch loadBefore actually invokes loadBeforeEx for step 2. This change was outlined in zopefoundation/ZODB#318 (comment) and zopefoundation/ZODB#318 (comment) and as explained in the first link this patch is also semantically coupled with zodb#484 This patch passes tests with both ZODB5 and with ZODB5+zopefoundation/ZODB#323: - when ran with ZODB5 it verifies that loadBefore implementation does not become broken. - when ran with ZODB5+zopefoundation/ZODB#323 it verifies that loadBeforeEx implementation is correct. For tests to pass with ZODB5+zopefoundation/ZODB#323 we also need zopefoundation/zc.zlibstorage#11 because without that fix zc.zlibstorage does not decompress data on loadBeforeEx.

Commits

Commits on Nov 11, 2021

Provide loadBeforeEx