Re: Further pg_upgrade analysis for many tables - Mailing list pgsql-hackers

From Dimitri Fontaine
Subject Re: Further pg_upgrade analysis for many tables
Date
Msg-id m2lie2a8jc.fsf@2ndQuadrant.fr
Whole thread Raw
In response to Re: Further pg_upgrade analysis for many tables  (Alvaro Herrera <alvherre@2ndquadrant.com>)
Responses Re: Further pg_upgrade analysis for many tables  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> Could we use some adaptive mechanism here?  Say we use a list for the
> first ten entries, and if an eleventh one comes in, we create a hash
> table for that one and all subsequent ones.  All future calls would
> have to examine both the list for the first few and then the hash table.

Is it necessary to do so? Do we know for sure that a 10 elements hash
table is slower than a 10 elements list when only doing key based
lookups, for the object data type we're interested into here?

-- 
Dimitri Fontaine
http://2ndQuadrant.fr     PostgreSQL : Expertise, Formation et Support



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