On 2024-Oct-03, jian he wrote: > I thought SearchSysCacheCopyAttNum is expensive. > Relation->rd_att is enough for checking attnotnull. > > What do you think of the following refactoring of set_attnotnull?
Eh, sure, why not. I mean, I expect that this is going to be barely noticeable performance-wise, but I don't see a reason not to do it this way. The new code in transformIndexConstraint() I added to verify NO INHERIT for columns in the PK[1] is likely to have a more noticeable impact: we have to scan the whole cxt->nnconstraints list for each column of the PK, and strcmp() the column names in order to find matches. I expect this this to be slow (and affect everybody) but I don't see any other reasonable way to do it. A possibility is to add a Constraint member to ColumnDef, and pre-process so that we attach the correct constraint definition to each column definition before invoking transformIndexConstraints in transformCreateStmt; we already do the match there, so it would be a good place for that. Alternatively, turn is_not_null into a tristate (yes, no, "yes but is no inherit"). [1] https://github.com/alvherre/postgres/commit/22e5820e241c744fb36cbc643a4d8d94162c562e -- Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/ "The problem with the facetime model is not just that it's demoralizing, but that the people pretending to work interrupt the ones actually working." -- Paul Graham, http://www.paulgraham.com/opensource.html
