Thiemo Kellner <thiemo@xxxxxxxxxxxxxxxxxxxx> writes: > I try to implement SCD2 on trigger level and try to generated needed > code on the fly. Therefore I need to read data about the objects in the > database. So far so good. I know of the information_schema and the > pg_catalog. The documentation for the information_schema states that it > 'is defined in the SQL standard and can therefore be expected to be > portable and remain stable'. I can think of a sensible meaning of > portable. One cannot port it to MariaDB, can one? If MariaDB implements information_schema according to the spec, then yes. (If they don't, that's something to complain about to them, not us.) > I created following query to get > the index columns of an index. I fear breakage when not run on the > specific version I developed it against. Is there a more elegant way by > the information_schema? No, because indexes are not a part of the SQL standard. (I'm not here to debate the wisdom of that choice; we didn't make it.) You can get information about constraints out of the information_schema, so to the extent that what you're interested in is the indexes underlying PK or UNIQUE constraints, that's an option. Otherwise, you're dealing with an implementation-specific feature and you shouldn't be surprised that the way of finding out about it is likewise implementation-specific. FWIW, the stuff used in your sample query has all been there for a very long time; we don't like to break plausible client queries lightly. regards, tom lane
