Shulou(Shulou.com)06/01 Report--

Numtrans; transno++) {/ / conversion function AggStatePerTrans pertrans = & aggstate- > pertrans [transno]; / / pergroup AggStatePerGroup pergroupstate; pergroupstate = & pergroup [Transno] If (pertrans- > numSortCols > 0) {/ /-there is DISTINCT/ORDER BY / / verification, and Hash does not need to sort Assert (aggstate- > aggstrategy! = AGG_HASHED & & aggstate- > aggstrategy! = AGG_MIXED) If (pertrans- > numInputs = = 1) / / separate process_ordered_aggregate_single (aggstate, pertrans, pergroupstate) Else / / multiple process_ordered_aggregate_multi (aggstate, pertrans, pergroupstate);}} / * * Run the final functions. * execute the function that gets the final value * / / traverses the aggregate for (aggno = 0; aggno)

Numaggs; aggno++) {/ / get peragg AggStatePerAgg peragg = & peraggs [aggno]; int transno = peragg- > transno; AggStatePerGroup pergroupstate; / / pergroup pergroupstate = & pergroup [transno] If (DO_AGGSPLIT_SKIPFINAL (aggstate- > aggsplit)) / / parallel processing result finalize_partialaggregate (aggstate, peragg, pergroupstate, & aggvalues [aggno], & aggnulls [aggno]) Else / / call finalize_aggregate to get the result finalize_aggregate (aggstate, peragg, pergroupstate, & aggvalues [aggno], & aggnulls [aggno]);}}

Project_aggregates

The project_aggregates function projects the results of a set (which have been calculated by the finalize_aggregates function).

/ * * Project the result of a group (whose aggs have already been calculated by * finalize_aggregates) Returns the result slot, or NULL if no row is * projected (suppressed by qual). * project a set of results (which have been calculated by the finalize_aggregates function). * returns the result slot, and returns NULL if there is no result row projection (processed by qual). * / static TupleTableSlot * project_aggregates (AggState * aggstate) {ExprContext * econtext = aggstate- > ss.ps.ps_ExprContext; / * * Check the qual (HAVING clause); if the group does not match, ignore it. * check conditional expressions (HAVING clause). If it does not match with group, ignore it. * / if (ExecQual (aggstate- > ss.ps.qual, econtext)) {/ * Form and return projection tuple using the aggregate results and * the representative input tuple. * use the aggregate result and the corresponding input tuple to form and return the projection tuple. * / return ExecProject (aggstate- > ss.ps.ps_ProjInfo);} else InstrCountFiltered1 (aggstate, 1); return NULL;} # define InstrCountFiltered1 (node, delta)\ do {\ if (PlanState *) (node))-> instrument)\ ((PlanState *) (node))-> instrument- > nfiltered1 + = (delta);\} while (0)

ExecProject

The ExecProject function projects tuples based on projection information and stores them in the slot parameter passed to ExecBuildProjectInfo ().

/ * ExecProject * * Projects a tuple based on projection info and stores it in the slot passed * to ExecBuildProjectInfo (). * projects tuples based on projection information and stores them in the slot parameter passed to ExecBuildProjectInfo (). * * Note: the result is always a virtual tuple; therefore it may reference * the contents of the exprContext's scan tuples and/or temporary results * constructed in the exprContext. If the caller wishes the result to be * valid longer than that data will be valid, he must call ExecMaterializeSlot * on the result slot. * Note: the result is usually a virtual tuple. Therefore, the tuple may rely on the contents of the exprContext scan tuple and / or temporary results built in exprContext. * if the caller wants the result to last longer than the data, the caller must call ExecMaterializeSlot (materialization) on the result slot. * / # ifndef FRONTENDstatic inline TupleTableSlot * ExecProject (ProjectionInfo * projInfo) {ExprContext * econtext = projInfo- > pi_exprContext; ExprState * state = & projInfo- > pi_state; TupleTableSlot * slot = state- > resultslot; bool isnull; / * * Clear any former contents of the result slot. This makes it safe for * us to use the slot's Datum/isnull arrays as workspace. * clear the form and content of the result slot. * this ensures that slot's Datum/isnull array is OK. * / ExecClearTuple (slot); / * Run the expression, discarding scalar result from the last column. * / / perform expression parsing and discard the scalar result. (void) ExecEvalExprSwitchContext (state, econtext, & isnull); / * Successfully formed a result row. Mark the result slot as containing a * valid virtual tuple (inlined version of ExecStoreVirtualTuple ()). * successfully form a result row. * the tag result slot contains valid virtual tuples (inline version of ExecStoreVirtualTuple) * / slot- > tts_isempty = false; slot- > tts_nvalid = slot- > tts_tupleDescriptor- > natts; return slot;} # endif 3. Tracking and analysis

N/A

IV. Reference materials

PostgreSQL Source Code interpretation (178)-query # 95 (aggregate function) # 1 related data structures

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