} PruneState;
/* Local functions */
+static void prune_freeze_setup(PruneFreezeParams *params,
+ TransactionId new_relfrozen_xid,
+ MultiXactId new_relmin_mxid,
+ const PruneFreezeResult *presult,
+ PruneState *prstate);
+static void prune_freeze_plan(Oid reloid, Buffer buffer,
+ PruneState *prstate,
+ OffsetNumber *off_loc);
static HTSV_Result heap_prune_satisfies_vacuum(PruneState *prstate,
HeapTuple tup,
Buffer buffer);
}
/*
- * Decide whether to proceed with freezing according to the freeze plans
- * prepared for the given heap buffer. If freezing is chosen, this function
- * performs several pre-freeze checks.
- *
- * The values of do_prune, do_hint_prune, and did_tuple_hint_fpi must be
- * determined before calling this function.
- *
- * prstate is both an input and output parameter.
- *
- * Returns true if we should apply the freeze plans and freeze tuples on the
- * page, and false otherwise.
- */
-static bool
-heap_page_will_freeze(Relation relation, Buffer buffer,
- bool did_tuple_hint_fpi,
- bool do_prune,
- bool do_hint_prune,
- PruneState *prstate)
-{
- bool do_freeze = false;
-
- /*
- * If the caller specified we should not attempt to freeze any tuples,
- * validate that everything is in the right state and return.
- */
- if (!prstate->attempt_freeze)
- {
- Assert(!prstate->all_frozen && prstate->nfrozen == 0);
- Assert(prstate->lpdead_items == 0 || !prstate->all_visible);
- return false;
- }
-
- if (prstate->pagefrz.freeze_required)
- {
- /*
- * heap_prepare_freeze_tuple indicated that at least one XID/MXID from
- * before FreezeLimit/MultiXactCutoff is present. Must freeze to
- * advance relfrozenxid/relminmxid.
- */
- do_freeze = true;
- }
- else
- {
- /*
- * Opportunistically freeze the page if we are generating an FPI
- * anyway and if doing so means that we can set the page all-frozen
- * afterwards (might not happen until VACUUM's final heap pass).
- *
- * XXX: Previously, we knew if pruning emitted an FPI by checking
- * pgWalUsage.wal_fpi before and after pruning. Once the freeze and
- * prune records were combined, this heuristic couldn't be used
- * anymore. The opportunistic freeze heuristic must be improved;
- * however, for now, try to approximate the old logic.
- */
- if (prstate->all_frozen && prstate->nfrozen > 0)
- {
- Assert(prstate->all_visible);
-
- /*
- * Freezing would make the page all-frozen. Have already emitted
- * an FPI or will do so anyway?
- */
- if (RelationNeedsWAL(relation))
- {
- if (did_tuple_hint_fpi)
- do_freeze = true;
- else if (do_prune)
- {
- if (XLogCheckBufferNeedsBackup(buffer))
- do_freeze = true;
- }
- else if (do_hint_prune)
- {
- if (XLogHintBitIsNeeded() && XLogCheckBufferNeedsBackup(buffer))
- do_freeze = true;
- }
- }
- }
- }
-
- if (do_freeze)
- {
- /*
- * Validate the tuples we will be freezing before entering the
- * critical section.
- */
- heap_pre_freeze_checks(buffer, prstate->frozen, prstate->nfrozen);
-
- /*
- * Calculate what the snapshot conflict horizon should be for a record
- * freezing tuples. We can use the visibility_cutoff_xid as our cutoff
- * for conflicts when the whole page is eligible to become all-frozen
- * in the VM once we're done with it. Otherwise, we generate a
- * conservative cutoff by stepping back from OldestXmin.
- */
- if (prstate->all_frozen)
- prstate->frz_conflict_horizon = prstate->visibility_cutoff_xid;
- else
- {
- /* Avoids false conflicts when hot_standby_feedback in use */
- prstate->frz_conflict_horizon = prstate->cutoffs->OldestXmin;
- TransactionIdRetreat(prstate->frz_conflict_horizon);
- }
- }
- else if (prstate->nfrozen > 0)
- {
- /*
- * The page contained some tuples that were not already frozen, and we
- * chose not to freeze them now. The page won't be all-frozen then.
- */
- Assert(!prstate->pagefrz.freeze_required);
-
- prstate->all_frozen = false;
- prstate->nfrozen = 0; /* avoid miscounts in instrumentation */
- }
- else
- {
- /*
- * We have no freeze plans to execute. The page might already be
- * all-frozen (perhaps only following pruning), though. Such pages
- * can be marked all-frozen in the VM by our caller, even though none
- * of its tuples were newly frozen here.
- */
- }
-
- return do_freeze;
-}
-
-
-/*
- * Prune and repair fragmentation and potentially freeze tuples on the
- * specified page.
- *
- * Caller must have pin and buffer cleanup lock on the page. Note that we
- * don't update the FSM information for page on caller's behalf. Caller might
- * also need to account for a reduction in the length of the line pointer
- * array following array truncation by us.
- *
- * params contains the input parameters used to control freezing and pruning
- * behavior. See the definition of PruneFreezeParams for more on what each
- * parameter does.
- *
- * If the HEAP_PAGE_PRUNE_FREEZE option is set in params, we will freeze
- * tuples if it's required in order to advance relfrozenxid / relminmxid, or
- * if it's considered advantageous for overall system performance to do so
- * now. The 'params.cutoffs', 'presult', 'new_relfrozen_xid' and
- * 'new_relmin_mxid' arguments are required when freezing. When
- * HEAP_PAGE_PRUNE_FREEZE option is passed, we also set presult->all_visible
- * and presult->all_frozen after determining whether or not to
- * opportunistically freeze, to indicate if the VM bits can be set. They are
- * always set to false when the HEAP_PAGE_PRUNE_FREEZE option is not passed,
- * because at the moment only callers that also freeze need that information.
- *
- * presult contains output parameters needed by callers, such as the number of
- * tuples removed and the offsets of dead items on the page after pruning.
- * heap_page_prune_and_freeze() is responsible for initializing it. Required
- * by all callers.
- *
- * off_loc is the offset location required by the caller to use in error
- * callback.
- *
- * new_relfrozen_xid and new_relmin_mxid must provided by the caller if the
- * HEAP_PAGE_PRUNE_FREEZE option is set in params. On entry, they contain the
- * oldest XID and multi-XID seen on the relation so far. They will be updated
- * with oldest values present on the page after pruning. After processing the
- * whole relation, VACUUM can use these values as the new
- * relfrozenxid/relminmxid for the relation.
+ * Helper for heap_page_prune_and_freeze() to initialize the PruneState using
+ * the provided parameters.
*/
-void
-heap_page_prune_and_freeze(PruneFreezeParams *params,
- PruneFreezeResult *presult,
- OffsetNumber *off_loc,
- TransactionId *new_relfrozen_xid,
- MultiXactId *new_relmin_mxid)
+static void
+prune_freeze_setup(PruneFreezeParams *params,
+ TransactionId new_relfrozen_xid,
+ MultiXactId new_relmin_mxid,
+ const PruneFreezeResult *presult,
+ PruneState *prstate)
{
- Buffer buffer = params->buffer;
- Page page = BufferGetPage(buffer);
- BlockNumber blockno = BufferGetBlockNumber(buffer);
- OffsetNumber offnum,
- maxoff;
- PruneState prstate;
- HeapTupleData tup;
- bool do_freeze;
- bool do_prune;
- bool do_hint_prune;
- bool did_tuple_hint_fpi;
- int64 fpi_before = pgWalUsage.wal_fpi;
-
/* Copy parameters to prstate */
- prstate.vistest = params->vistest;
- prstate.mark_unused_now =
+ prstate->vistest = params->vistest;
+ prstate->mark_unused_now =
(params->options & HEAP_PAGE_PRUNE_MARK_UNUSED_NOW) != 0;
/* cutoffs must be provided if we will attempt freezing */
Assert(!(params->options & HEAP_PAGE_PRUNE_FREEZE) || params->cutoffs);
- prstate.attempt_freeze = (params->options & HEAP_PAGE_PRUNE_FREEZE) != 0;
- prstate.cutoffs = params->cutoffs;
+ prstate->attempt_freeze = (params->options & HEAP_PAGE_PRUNE_FREEZE) != 0;
+ prstate->cutoffs = params->cutoffs;
/*
* Our strategy is to scan the page and make lists of items to change,
* prunable, we will save the lowest relevant XID in new_prune_xid. Also
* initialize the rest of our working state.
*/
- prstate.new_prune_xid = InvalidTransactionId;
- prstate.latest_xid_removed = InvalidTransactionId;
- prstate.nredirected = prstate.ndead = prstate.nunused = prstate.nfrozen = 0;
- prstate.nroot_items = 0;
- prstate.nheaponly_items = 0;
+ prstate->new_prune_xid = InvalidTransactionId;
+ prstate->latest_xid_removed = InvalidTransactionId;
+ prstate->nredirected = prstate->ndead = prstate->nunused = 0;
+ prstate->nfrozen = 0;
+ prstate->nroot_items = 0;
+ prstate->nheaponly_items = 0;
/* initialize page freezing working state */
- prstate.pagefrz.freeze_required = false;
- if (prstate.attempt_freeze)
+ prstate->pagefrz.freeze_required = false;
+ if (prstate->attempt_freeze)
{
- Assert(new_relfrozen_xid && new_relmin_mxid);
- prstate.pagefrz.FreezePageRelfrozenXid = *new_relfrozen_xid;
- prstate.pagefrz.NoFreezePageRelfrozenXid = *new_relfrozen_xid;
- prstate.pagefrz.FreezePageRelminMxid = *new_relmin_mxid;
- prstate.pagefrz.NoFreezePageRelminMxid = *new_relmin_mxid;
+ prstate->pagefrz.FreezePageRelfrozenXid = new_relfrozen_xid;
+ prstate->pagefrz.NoFreezePageRelfrozenXid = new_relfrozen_xid;
+ prstate->pagefrz.FreezePageRelminMxid = new_relmin_mxid;
+ prstate->pagefrz.NoFreezePageRelminMxid = new_relmin_mxid;
}
else
{
- Assert(new_relfrozen_xid == NULL && new_relmin_mxid == NULL);
- prstate.pagefrz.FreezePageRelminMxid = InvalidMultiXactId;
- prstate.pagefrz.NoFreezePageRelminMxid = InvalidMultiXactId;
- prstate.pagefrz.FreezePageRelfrozenXid = InvalidTransactionId;
- prstate.pagefrz.NoFreezePageRelfrozenXid = InvalidTransactionId;
+ Assert(new_relfrozen_xid == InvalidTransactionId &&
+ new_relmin_mxid == InvalidMultiXactId);
+ prstate->pagefrz.FreezePageRelminMxid = InvalidMultiXactId;
+ prstate->pagefrz.NoFreezePageRelminMxid = InvalidMultiXactId;
+ prstate->pagefrz.FreezePageRelfrozenXid = InvalidTransactionId;
+ prstate->pagefrz.NoFreezePageRelfrozenXid = InvalidTransactionId;
}
- prstate.ndeleted = 0;
- prstate.live_tuples = 0;
- prstate.recently_dead_tuples = 0;
- prstate.hastup = false;
- prstate.lpdead_items = 0;
- prstate.deadoffsets = presult->deadoffsets;
- prstate.frz_conflict_horizon = InvalidTransactionId;
+ prstate->ndeleted = 0;
+ prstate->live_tuples = 0;
+ prstate->recently_dead_tuples = 0;
+ prstate->hastup = false;
+ prstate->lpdead_items = 0;
+ prstate->deadoffsets = (OffsetNumber *) presult->deadoffsets;
+ prstate->frz_conflict_horizon = InvalidTransactionId;
/*
- * Caller may update the VM after we're done. We can keep track of
+ * Vacuum may update the VM after we're done. We can keep track of
* whether the page will be all-visible and all-frozen after pruning and
* freezing to help the caller to do that.
*
* all_frozen before we return them to the caller, so that the caller
* doesn't set the VM bits incorrectly.
*/
- if (prstate.attempt_freeze)
+ if (prstate->attempt_freeze)
{
- prstate.all_visible = true;
- prstate.all_frozen = true;
+ prstate->all_visible = true;
+ prstate->all_frozen = true;
}
else
{
* Initializing to false allows skipping the work to update them in
* heap_prune_record_unchanged_lp_normal().
*/
- prstate.all_visible = false;
- prstate.all_frozen = false;
+ prstate->all_visible = false;
+ prstate->all_frozen = false;
}
/*
* running transaction on the standby does not see tuples on the page as
* all-visible, so the conflict horizon remains InvalidTransactionId.
*/
- prstate.visibility_cutoff_xid = InvalidTransactionId;
+ prstate->visibility_cutoff_xid = InvalidTransactionId;
+}
- maxoff = PageGetMaxOffsetNumber(page);
- tup.t_tableOid = RelationGetRelid(params->relation);
+/*
+ * Helper for heap_page_prune_and_freeze(). Iterates over every tuple on the
+ * page, examines its visibility information, and determines the appropriate
+ * action for each tuple. All tuples are processed and classified during this
+ * phase, but no modifications are made to the page until the later execution
+ * stage.
+ *
+ * *off_loc is used for error callback and cleared before returning.
+ */
+static void
+prune_freeze_plan(Oid reloid, Buffer buffer, PruneState *prstate,
+ OffsetNumber *off_loc)
+{
+ Page page = BufferGetPage(buffer);
+ BlockNumber blockno = BufferGetBlockNumber(buffer);
+ OffsetNumber maxoff = PageGetMaxOffsetNumber(page);
+ OffsetNumber offnum;
+ HeapTupleData tup;
+
+ tup.t_tableOid = reloid;
/*
* Determine HTSV for all tuples, and queue them up for processing as HOT
*/
*off_loc = offnum;
- prstate.processed[offnum] = false;
- prstate.htsv[offnum] = -1;
+ prstate->processed[offnum] = false;
+ prstate->htsv[offnum] = -1;
/* Nothing to do if slot doesn't contain a tuple */
if (!ItemIdIsUsed(itemid))
{
- heap_prune_record_unchanged_lp_unused(page, &prstate, offnum);
+ heap_prune_record_unchanged_lp_unused(page, prstate, offnum);
continue;
}
* If the caller set mark_unused_now true, we can set dead line
* pointers LP_UNUSED now.
*/
- if (unlikely(prstate.mark_unused_now))
- heap_prune_record_unused(&prstate, offnum, false);
+ if (unlikely(prstate->mark_unused_now))
+ heap_prune_record_unused(prstate, offnum, false);
else
- heap_prune_record_unchanged_lp_dead(page, &prstate, offnum);
+ heap_prune_record_unchanged_lp_dead(page, prstate, offnum);
continue;
}
if (ItemIdIsRedirected(itemid))
{
/* This is the start of a HOT chain */
- prstate.root_items[prstate.nroot_items++] = offnum;
+ prstate->root_items[prstate->nroot_items++] = offnum;
continue;
}
tup.t_len = ItemIdGetLength(itemid);
ItemPointerSet(&tup.t_self, blockno, offnum);
- prstate.htsv[offnum] = heap_prune_satisfies_vacuum(&prstate, &tup,
- buffer);
+ prstate->htsv[offnum] = heap_prune_satisfies_vacuum(prstate, &tup,
+ buffer);
if (!HeapTupleHeaderIsHeapOnly(htup))
- prstate.root_items[prstate.nroot_items++] = offnum;
+ prstate->root_items[prstate->nroot_items++] = offnum;
else
- prstate.heaponly_items[prstate.nheaponly_items++] = offnum;
+ prstate->heaponly_items[prstate->nheaponly_items++] = offnum;
}
- /*
- * If checksums are enabled, heap_prune_satisfies_vacuum() may have caused
- * an FPI to be emitted.
- */
- did_tuple_hint_fpi = fpi_before != pgWalUsage.wal_fpi;
-
/*
* Process HOT chains.
*
* the page instead of using the root_items array, also did it in
* ascending offset number order.)
*/
- for (int i = prstate.nroot_items - 1; i >= 0; i--)
+ for (int i = prstate->nroot_items - 1; i >= 0; i--)
{
- offnum = prstate.root_items[i];
+ offnum = prstate->root_items[i];
/* Ignore items already processed as part of an earlier chain */
- if (prstate.processed[offnum])
+ if (prstate->processed[offnum])
continue;
/* see preceding loop */
*off_loc = offnum;
/* Process this item or chain of items */
- heap_prune_chain(page, blockno, maxoff, offnum, &prstate);
+ heap_prune_chain(page, blockno, maxoff, offnum, prstate);
}
/*
* Process any heap-only tuples that were not already processed as part of
* a HOT chain.
*/
- for (int i = prstate.nheaponly_items - 1; i >= 0; i--)
+ for (int i = prstate->nheaponly_items - 1; i >= 0; i--)
{
- offnum = prstate.heaponly_items[i];
+ offnum = prstate->heaponly_items[i];
- if (prstate.processed[offnum])
+ if (prstate->processed[offnum])
continue;
/* see preceding loop */
* return true for an XMIN_INVALID tuple, so this code will work even
* when there were sequential updates within the aborted transaction.)
*/
- if (prstate.htsv[offnum] == HEAPTUPLE_DEAD)
+ if (prstate->htsv[offnum] == HEAPTUPLE_DEAD)
{
ItemId itemid = PageGetItemId(page, offnum);
HeapTupleHeader htup = (HeapTupleHeader) PageGetItem(page, itemid);
if (likely(!HeapTupleHeaderIsHotUpdated(htup)))
{
HeapTupleHeaderAdvanceConflictHorizon(htup,
- &prstate.latest_xid_removed);
- heap_prune_record_unused(&prstate, offnum, true);
+ &prstate->latest_xid_removed);
+ heap_prune_record_unused(prstate, offnum, true);
}
else
{
}
}
else
- heap_prune_record_unchanged_lp_normal(page, &prstate, offnum);
+ heap_prune_record_unchanged_lp_normal(page, prstate, offnum);
}
/* We should now have processed every tuple exactly once */
{
*off_loc = offnum;
- Assert(prstate.processed[offnum]);
+ Assert(prstate->processed[offnum]);
}
#endif
/* Clear the offset information once we have processed the given page. */
*off_loc = InvalidOffsetNumber;
+}
+
+/*
+ * Decide whether to proceed with freezing according to the freeze plans
+ * prepared for the given heap buffer. If freezing is chosen, this function
+ * performs several pre-freeze checks.
+ *
+ * The values of do_prune, do_hint_prune, and did_tuple_hint_fpi must be
+ * determined before calling this function.
+ *
+ * prstate is both an input and output parameter.
+ *
+ * Returns true if we should apply the freeze plans and freeze tuples on the
+ * page, and false otherwise.
+ */
+static bool
+heap_page_will_freeze(Relation relation, Buffer buffer,
+ bool did_tuple_hint_fpi,
+ bool do_prune,
+ bool do_hint_prune,
+ PruneState *prstate)
+{
+ bool do_freeze = false;
+
+ /*
+ * If the caller specified we should not attempt to freeze any tuples,
+ * validate that everything is in the right state and return.
+ */
+ if (!prstate->attempt_freeze)
+ {
+ Assert(!prstate->all_frozen && prstate->nfrozen == 0);
+ Assert(prstate->lpdead_items == 0 || !prstate->all_visible);
+ return false;
+ }
+
+ if (prstate->pagefrz.freeze_required)
+ {
+ /*
+ * heap_prepare_freeze_tuple indicated that at least one XID/MXID from
+ * before FreezeLimit/MultiXactCutoff is present. Must freeze to
+ * advance relfrozenxid/relminmxid.
+ */
+ do_freeze = true;
+ }
+ else
+ {
+ /*
+ * Opportunistically freeze the page if we are generating an FPI
+ * anyway and if doing so means that we can set the page all-frozen
+ * afterwards (might not happen until VACUUM's final heap pass).
+ *
+ * XXX: Previously, we knew if pruning emitted an FPI by checking
+ * pgWalUsage.wal_fpi before and after pruning. Once the freeze and
+ * prune records were combined, this heuristic couldn't be used
+ * anymore. The opportunistic freeze heuristic must be improved;
+ * however, for now, try to approximate the old logic.
+ */
+ if (prstate->all_frozen && prstate->nfrozen > 0)
+ {
+ Assert(prstate->all_visible);
+
+ /*
+ * Freezing would make the page all-frozen. Have already emitted
+ * an FPI or will do so anyway?
+ */
+ if (RelationNeedsWAL(relation))
+ {
+ if (did_tuple_hint_fpi)
+ do_freeze = true;
+ else if (do_prune)
+ {
+ if (XLogCheckBufferNeedsBackup(buffer))
+ do_freeze = true;
+ }
+ else if (do_hint_prune)
+ {
+ if (XLogHintBitIsNeeded() && XLogCheckBufferNeedsBackup(buffer))
+ do_freeze = true;
+ }
+ }
+ }
+ }
+
+ if (do_freeze)
+ {
+ /*
+ * Validate the tuples we will be freezing before entering the
+ * critical section.
+ */
+ heap_pre_freeze_checks(buffer, prstate->frozen, prstate->nfrozen);
+
+ /*
+ * Calculate what the snapshot conflict horizon should be for a record
+ * freezing tuples. We can use the visibility_cutoff_xid as our cutoff
+ * for conflicts when the whole page is eligible to become all-frozen
+ * in the VM once we're done with it. Otherwise, we generate a
+ * conservative cutoff by stepping back from OldestXmin.
+ */
+ if (prstate->all_frozen)
+ prstate->frz_conflict_horizon = prstate->visibility_cutoff_xid;
+ else
+ {
+ /* Avoids false conflicts when hot_standby_feedback in use */
+ prstate->frz_conflict_horizon = prstate->cutoffs->OldestXmin;
+ TransactionIdRetreat(prstate->frz_conflict_horizon);
+ }
+ }
+ else if (prstate->nfrozen > 0)
+ {
+ /*
+ * The page contained some tuples that were not already frozen, and we
+ * chose not to freeze them now. The page won't be all-frozen then.
+ */
+ Assert(!prstate->pagefrz.freeze_required);
+
+ prstate->all_frozen = false;
+ prstate->nfrozen = 0; /* avoid miscounts in instrumentation */
+ }
+ else
+ {
+ /*
+ * We have no freeze plans to execute. The page might already be
+ * all-frozen (perhaps only following pruning), though. Such pages
+ * can be marked all-frozen in the VM by our caller, even though none
+ * of its tuples were newly frozen here.
+ */
+ }
+
+ return do_freeze;
+}
+
+
+/*
+ * Prune and repair fragmentation and potentially freeze tuples on the
+ * specified page.
+ *
+ * Caller must have pin and buffer cleanup lock on the page. Note that we
+ * don't update the FSM information for page on caller's behalf. Caller might
+ * also need to account for a reduction in the length of the line pointer
+ * array following array truncation by us.
+ *
+ * params contains the input parameters used to control freezing and pruning
+ * behavior. See the definition of PruneFreezeParams for more on what each
+ * parameter does.
+ *
+ * If the HEAP_PAGE_PRUNE_FREEZE option is set in params, we will freeze
+ * tuples if it's required in order to advance relfrozenxid / relminmxid, or
+ * if it's considered advantageous for overall system performance to do so
+ * now. The 'params.cutoffs', 'presult', 'new_relfrozen_xid' and
+ * 'new_relmin_mxid' arguments are required when freezing. When
+ * HEAP_PAGE_PRUNE_FREEZE option is passed, we also set presult->all_visible
+ * and presult->all_frozen after determining whether or not to
+ * opportunistically freeze, to indicate if the VM bits can be set. They are
+ * always set to false when the HEAP_PAGE_PRUNE_FREEZE option is not passed,
+ * because at the moment only callers that also freeze need that information.
+ *
+ * presult contains output parameters needed by callers, such as the number of
+ * tuples removed and the offsets of dead items on the page after pruning.
+ * heap_page_prune_and_freeze() is responsible for initializing it. Required
+ * by all callers.
+ *
+ * off_loc is the offset location required by the caller to use in error
+ * callback.
+ *
+ * new_relfrozen_xid and new_relmin_mxid must be provided by the caller if the
+ * HEAP_PAGE_PRUNE_FREEZE option is set in params. On entry, they contain the
+ * oldest XID and multi-XID seen on the relation so far. They will be updated
+ * with the oldest values present on the page after pruning. After processing
+ * the whole relation, VACUUM can use these values as the new
+ * relfrozenxid/relminmxid for the relation.
+ */
+void
+heap_page_prune_and_freeze(PruneFreezeParams *params,
+ PruneFreezeResult *presult,
+ OffsetNumber *off_loc,
+ TransactionId *new_relfrozen_xid,
+ MultiXactId *new_relmin_mxid)
+{
+ Buffer buffer = params->buffer;
+ Page page = BufferGetPage(buffer);
+ PruneState prstate;
+ bool do_freeze;
+ bool do_prune;
+ bool do_hint_prune;
+ bool did_tuple_hint_fpi;
+ int64 fpi_before = pgWalUsage.wal_fpi;
+
+ /* Initialize prstate */
+ prune_freeze_setup(params,
+ new_relfrozen_xid ?
+ *new_relfrozen_xid : InvalidTransactionId,
+ new_relmin_mxid ?
+ *new_relmin_mxid : InvalidMultiXactId,
+ presult,
+ &prstate);
+
+ /*
+ * Examine all line pointers and tuple visibility information to determine
+ * which line pointers should change state and which tuples may be frozen.
+ * Prepare queue of state changes to later be executed in a critical
+ * section.
+ */
+ prune_freeze_plan(RelationGetRelid(params->relation),
+ buffer, &prstate, off_loc);
+
+ /*
+ * If checksums are enabled, calling heap_prune_satisfies_vacuum() while
+ * checking tuple visibility information in prune_freeze_plan() may have
+ * caused an FPI to be emitted.
+ */
+ did_tuple_hint_fpi = fpi_before != pgWalUsage.wal_fpi;
do_prune = prstate.nredirected > 0 ||
prstate.ndead > 0 ||
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