bug in information_schema?
От | Kyle Bateman |
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Тема | bug in information_schema? |
Дата | |
Msg-id | 42EB0700.4040600@actarg.com обсуждение исходный текст |
Ответы |
Re: bug in information_schema?
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Список | pgsql-sql |
I noticed that it seemed a bit slow to query information_schema.view_column_usage. As I look at the code in information_schema.sql, I'm not sure why pg_user is referenced twice (once without an alias). It looks like we can take out the first pg_user and remove the DISTINCT keyword and this improves the efficiency significantly. It seems to return the same result but in half the time. Anyone see a problem with this? (The same problem may also be in view_table_usage but I haven't done any testing there yet.) Code from information_schema.sql: CREATE VIEW view_column_usage AS SELECT DISTINCT CAST(current_database() AS sql_identifier) AS view_catalog, CAST(nv.nspname AS sql_identifier) AS view_schema, CAST(v.relname AS sql_identifier) AS view_name, CAST(current_database() AS sql_identifier) AS table_catalog, CAST(nt.nspname AS sql_identifier) AS table_schema, CAST(t.relname AS sql_identifier) AS table_name, CAST(a.attname AS sql_identifier) AS column_name FROM pg_user, pg_namespace nv, pg_class v, pg_depend dv, pg_depend dt, pg_class t, pg_namespace nt, pg_attributea, pg_user u
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