Hello!
I'm interested in SELECT ... FOR SHARE 8.1 feature. I'd tried to measure performance degradation and got something about 30-60% for queries retrieve a lot of rows. Is it realistic estimation? Does this penalty depend on something (data types, triggers, foreign keys, whatever) significantly? Is any sort of lock escalation [and other unpreditable things] involved here?
Last question. What about ISOLATION LEVEL REPEATABLE READ syntax since non-exclusive locking for all SELECTs means [as far as I understand] nothing but REPEATABLE READ?
Thanks.
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Best regards
Ilja Golshtein