My question is about computed colums and slownes issue.
Table has several computed columns some of them which are persistent and indexed.
I observed that slowness even though the computed column is not used in stored procedures using this table. Queries are pulling indexed fields.
My other observation is that the slowness changes with the SET QUOTED_IDENTIFIER ON / OFF state.
My question is, should i open this parameter everywhere that uses the table? Do I need to open it wherever the table is selected, joined or updated? I don't fully understand the effect of this parameter.