Function cdbexplain_showExecStatsBegin

src/backend/commands/explain_gp.c:1487–1512

* cdbexplain_showExecStatsBegin * Called by qDisp process to create a CdbExplain_ShowStatCtx structure * in which to accumulate overall statistics for a query. * * 'querystarttime' is the timestamp of the start of the query, in a * platform-dependent format. * * Note this function is called before ExecutorStart(), so there is no EState * or SliceTable yet. */

 * or SliceTable yet.
 */
struct CdbExplain_ShowStatCtx *
cdbexplain_showExecStatsBegin(struct QueryDesc *queryDesc,
							  instr_time querystarttime)
{
	CdbExplain_ShowStatCtx *ctx;
	int			nslice;

	Assert(Gp_role != GP_ROLE_EXECUTE);

	/* Allocate and zero the ShowStatCtx */
	ctx = (CdbExplain_ShowStatCtx *) palloc0(sizeof(*ctx));

	ctx->querystarttime = querystarttime;

	/* Determine number of slices.  (SliceTable hasn't been built yet.) */
	nslice = queryDesc->plannedstmt->numSlices;

	/* Allocate and zero the SliceSummary array. */
	ctx->nslice = nslice;
	ctx->slices = (CdbExplain_SliceSummary *) palloc0(nslice * sizeof(ctx->slices[0]));

	/* Allocate a buffer in which we can collect any extra message text. */
	initStringInfoOfSize(&ctx->extratextbuf, 4000);

	return ctx;
}								/* cdbexplain_showExecStatsBegin */

/*
 * cdbexplain_showStatCtxFree