/* ----------------------------------------------------------------
* ExecReScanIndexOnlyScan(node)
*
* Recalculates the values of any scan keys whose value depends on
* information known at runtime, then rescans the indexed relation.
*
* Updating the scan key was formerly done separately in
* ExecUpdateIndexScanKeys. Integrating it into ReScan makes
* rescans of indices and relations/general streams more uniform.
* ----------------------------------------------------------------
*/
void
ExecReScanIndexOnlyScan(IndexOnlyScanState *node)
{
bool reset_parallel_scan = true;
/*
* If we are here to just update the scan keys, then don't reset parallel
* scan. For detailed reason behind this look in the comments for
* ExecReScanIndexScan.
*/
if (node->ioss_NumRuntimeKeys != 0 && !node->ioss_RuntimeKeysReady)
reset_parallel_scan = false;
/*
* If we are doing runtime key calculations (ie, any of the index key
* values weren't simple Consts), compute the new key values. But first,
* reset the context so we don't leak memory as each outer tuple is
* scanned. Note this assumes that we will recalculate *all* runtime keys
* on each call.
*/
if (node->ioss_NumRuntimeKeys != 0)
{
ExprContext *econtext = node->ioss_RuntimeContext;
ResetExprContext(econtext);
ExecIndexEvalRuntimeKeys(econtext,
node->ioss_RuntimeKeys,
node->ioss_NumRuntimeKeys);
}
node->ioss_RuntimeKeysReady = true;
/* reset index scan */
if (node->ioss_ScanDesc)
{
index_rescan(node->ioss_ScanDesc,
node->ioss_ScanKeys, node->ioss_NumScanKeys,
node->ioss_OrderByKeys, node->ioss_NumOrderByKeys);
if (reset_parallel_scan && node->ioss_ScanDesc->parallel_scan)
index_parallelrescan(node->ioss_ScanDesc);
}
ExecScanReScan(&node->ss);
}
/* ----------------------------------------------------------------
* ExecIndexOnlyScanReInitializeDSM
*
* Reset shared state before beginning a fresh scan.
* ----------------------------------------------------------------
*/
void
ExecIndexOnlyScanReInitializeDSM(IndexOnlyScanState *node,
ParallelContext *pcxt)
{
index_parallelrescan(node->ioss_ScanDesc);
}
