PostGIS
2.4.9dev-r@@SVN_REVISION@@
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PG_FUNCTION_INFO_V1 | ( | gserialized_analyze_nd | ) |
This function will be called when the ANALYZE command is run on a column of the "geometry" or "geography" type.
It will need to return a stats builder function reference and a "minimum" sample rows to feed it. If we want analisys to be completely skipped we can return FALSE and leave output vals untouched.
What we know from this call is:
o The pg_attribute row referring to the specific column. Could be used to get reltuples from pg_class (which might quite inexact though...) and use them to set an appropriate minimum number of sample rows to feed to the stats builder. The stats builder will also receive a more accurate "estimation" of the number or rows. o The pg_type row for the specific column. Could be used to set stat builder / sample rows based on domain type (when postgis will be implemented that way).
Being this experimental we'll stick to a static stat_builder/sample_rows value for now.