[pgpool-general: 8355] Re: Cache entries

Tatsuo Ishii ishii at sraoss.co.jp
Wed Aug 17 11:09:33 JST 2022

> Moreover I found something very weird.
> In case you add something to unsafe table in order not to cache queries
> from this table.
> Pgpool still increment num selects with those queries and this increase
> harm the cache hit ratio.
> I am missing something?
> Unsafe = city
> Select from city … let’s say 10 times
> Show pool_cache will show
> Num selects = 10

That's an expected behavior.

cache_hit_ratio = num_cache_hits / (num_cache_hits + num_selects)

where num_cache_hits is the total number of queries hitting query
cache, and num_selects is the total number of queries (regardless
hitting query cache or not).

So the number you showed looks correct.

Best reagards,
Tatsuo Ishii
English: http://www.sraoss.co.jp/index_en.php

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