Function ExplainCompositeScanCore

pg_documentdb/src/index_am/rum.c:1791–1847

static void
ExplainCompositeScanCore(IndexScanDesc scan, void *state,
						 ExplainWriterFuncs *writerFuncs)
{
	DocumentDBRumIndexState *outerScanState =
		(DocumentDBRumIndexState *) scan->opaque;

	writerFuncs->writeBool("isMultiKey",
						   outerScanState->multiKeyStatus ==
						   IndexMultiKeyStatus_HasArrays,
						   state);

	if (outerScanState->hasCorrelatedReducedTerms)
	{
		writerFuncs->writeBool("hasCorrelatedTerms", true, state);
	}

	bool hasTruncation = RumGetTruncationStatus(scan->indexRelation);
	if (hasTruncation)
	{
		writerFuncs->writeBool("hasTruncation", true, state);
	}

	if (outerScanState->compositeKey.sk_argument != (Datum) 0)
	{
		List *rawPerPathBounds = NIL;
		List *boundsList = GetIndexBoundsForExplain(
			scan->indexRelation,
			outerScanState->compositeKey.sk_argument,
			scan->numberOfOrderBys > 0, &rawPerPathBounds);

		if (rawPerPathBounds != NIL)
		{
			writerFuncs->writeStringList("startBounds", boundsList, state);
			writerFuncs->writeStringList("rawBounds", rawPerPathBounds, state);
		}
		else
		{
			writerFuncs->writeStringList("indexBounds", boundsList, state);
		}
	}

	if (outerScanState->numDuplicates > 0)
	{
		/* If we have duplicates, explain the number of duplicates */
		writerFuncs->writeInteger("numDuplicates", "entries",
								  outerScanState->numDuplicates, state);
	}

	if (ScanDirectionIsBackward(outerScanState->scanDirection))
	{
		writerFuncs->writeBool("isBackwardScan", true, state);
	}

	/* Explain the inner scan using underlying am */
	TryExplainByIndexAm(outerScanState->innerScan, writerFuncs, state);
}