On 2016/04/15 18:46, Ashutosh Bapat wrote: > > 3. PartitionKeyData contains KeyTypeCollInfo, whose contents can be > obtained by calling functions exprType, exprTypemod on partexprs. Why do we > need to store that information as a separate member?
There was no KeyTypeCollInfo in early days of the patch and then I found myself doing a lot of:
partexprs_item = list_head(key->partexprs); for (attr in key->partattrs) { if (attr->attnum != 0) { // simple column reference, get type from attr } else { // expression, get type using exprType, etc. partexprs_item = lnext(partexprs_item); } }
At least the two loops can be flattened to a single loop if we keep only expressions list with attributes being just Var nodes. exprType() etc. would then work seemlessly.
That ended up being quite a few places (though I managed to reduce the number of places over time). So, I created this struct which is initialized when partition key is built (on first open of the partitioned table).
Hmm, I am just afraid that we might end up with some code using cached information and some using exprType, exprTypmod etc.
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Best Wishes, Ashutosh Bapat EnterpriseDB Corporation The Postgres Database Company
