Re: pg_stat_statements: calls under-estimation propagation - Mailing list pgsql-hackers

From Sameer Thakur
Subject Re: pg_stat_statements: calls under-estimation propagation
Date
Msg-id CABzZFEtHoVabnas5aVxEi_4qZ4yLm99SZVxt4A5CUKEJ-yN=xg@mail.gmail.com
Whole thread Raw
In response to Re: pg_stat_statements: calls under-estimation propagation  (Alvaro Herrera <alvherre@2ndquadrant.com>)
List pgsql-hackers
<div class="shrinkable-quote">> This paragraph reads a bit strange to me: <br />> <br />> +  A statistics
sessionis the time period when statistics are gathered by <br />> statistics collector <br />> +  without being
reset.So a statistics session continues across normal <br />> shutdowns, <br />> +  but whenever statistics are
reset,like during a crash or upgrade, a new <br />> time period <br />> +  of statistics collection commences
i.e.a new statistics session. <br />> +  The query_id value generation is linked to statistics session to <br />>
emphasizethe fact <br />> +  that whenever statistics are reset,the query_id for the same queries will <br />>
alsochange. <br />> <br />> "time period when"?  Shouldn't that be "time period during which". <br />> Also,
doesn'ta new "statistics session" start when a stats reset is <br />> invoked by the user?  The bit after
"commences"appears correct (to me, <br />> not a native by any means) but seems also a bit strange. <br />>
</div>Ihave tried to rephrase this. Hopefully less confusing <br /><br /> A statistics session refers to the time
periodwhen statement <br />statistics are gathered by <br />statistics collector. A statistics session persists across
normal<br />shutdowns. Whenever statistics are reset like during a crash or upgrade, a new <br />statistics session
starts.The query_id value generation is linked to <br />statistics session to <br />emphasize that whenever statistics
arereset,the query_id for the same <br />queries will also change. <br /><br />regards <br />Sameer <br /><br /><hr
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