Jozef Ševčík wrote:
Richard, thanks for the answer. In fact, I double-quoted identifiers only because PgSQL forced me to do so when using capitalized letters in table/column name.
Well, if you don't quote them they get folded to lower-case and you get case-insensitive matching.
CREATE TABLE MyTable1 (a int); -- ends up as mytable1 CREATE TABLE "MyTable2" (a int); -- stays as MyTable2 SELECT * FROM MyTable1; -- OK, looks for "mytable1" SELECT * FROM MYTABLE1; -- also OK SELECT * FROM MyTaBlE1; -- also OK SELECT * FROM "MyTable1";-- Fails, looks for "MyTable1" SELECT * FROM MyTable2; -- Fails, looks for "mytable2" SELECT * FROM "MyTable2"; -- OK
I'm OK with this if it's PgSQL requirement (app runs on NHibernate so I just change column="MyColumn" to column="`MyColumn`" in mapping files). In fact I like capitalized column/table names (more readable for me), but the point is if this affect performance when running queries (for example PgSQL engine might take more time to analyze query with double-quoted identifiers or so). Is there any performance penalty for this ?
As I said, no cost you'll ever notice. -- Richard Huxton Archonet Ltd
