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Num_hashes) {/ * * Switch to next grouping set, reinitialize, and restart the * loop. * switch to the next grouping set, reinitialize and restart the loop * / select_current_set (aggstate, nextset, true); perhash = & aggstate- > Perhash [aggstate-> current_set]; ResetTupleHashIterator (perhash- > hashtable, & perhash- > hashiter); continue } else {/ * No more hashtables, so done * / / has completed the search, set the tag, and exit aggstate- > agg_done = true; return NULL }} / * * Clear the per-output-tuple context for each group * clear the per-output-tuple context for each group * * We intentionally don't use ReScanExprContext here; if any aggs have * registered shutdown callbacks, they mustn't be called yet, since we * might not be done with that agg. * ReScanExprContext will not be used here. If there is an aggs that registers the shutdown callback, * it should not be called yet, because we may not have finished processing the agg. * / ResetExprContext (econtext); / * * Transform representative tuple back into one with the right * columns. * turn the typical tuple back to the tuple with the correct column. * / ExecStoreMinimalTuple (entry- > firstTuple, hashslot, false); slot_getallattrs (hashslot); / Clean tuples / / reset firstSlot ExecClearTuple (firstSlot); memset (firstSlot- > tts_isnull, true, firstSlot- > tts_tupleDescriptor- > natts * sizeof (bool)); for (I = 0; I

NumhashGrpCols; iTunes +) {/ / reset firstSlot int varNumber = perhash- > hashGrpColIdxInput [I]-1; firstSlot- > tts_ values [varNumber] = hashslot- > tts_ values [I]; firstSlot- > tts_ isnull [varNumber] = hashslot- > tts_ isnull [I];} ExecStoreVirtualTuple (firstSlot); pergroup = (AggStatePerGroup) entry- > additional / * * Use the representative input tuple for any references to * non-aggregated input columns in the qual and tlist. * use typical input tuples for non-aggregate input column dependencies in qual and tlist * / econtext- > ecxt_outertuple = firstSlot; / / prepare projection slot prepare_projection_slot (aggstate, econtext- > ecxt_outertuple, aggstate- > current_set) / / the final aggregation operation finalize_aggregates (aggstate, peragg, pergroup); / / projection result = project_aggregates (aggstate); if (result) return result;} / * No more groups * / there is no more groups. Return NULL return NULL;} "how to use the PostgreSQL ExecAgg function". Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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