typedef enum XidCommitStatus
{
XID_COMMITTED,
+ XID_IS_CURRENT_XID,
XID_IN_PROGRESS,
XID_ABORTED
} XidCommitStatus;
TransactionId oldest_xid; /* ShmemVariableCache->oldestXid */
FullTransactionId oldest_fxid; /* 64-bit version of oldest_xid, computed
* relative to next_fxid */
+ TransactionId safe_xmin; /* this XID and newer ones can't become
+ * all-visible while we're running */
/*
* Cached copy of value from MultiXactState
uint32 offset; /* offset in tuple data */
AttrNumber attnum;
+ /* True if tuple's xmax makes it eligible for pruning */
+ bool tuple_could_be_pruned;
+
/* Values for iterating over toast for the attribute */
int32 chunkno;
int32 attrsize;
static void check_toast_tuple(HeapTuple toasttup, HeapCheckContext *ctx);
static bool check_tuple_attribute(HeapCheckContext *ctx);
-static bool check_tuple_header_and_visibilty(HeapTupleHeader tuphdr,
- HeapCheckContext *ctx);
+static bool check_tuple_header(HeapCheckContext *ctx);
+static bool check_tuple_visibility(HeapCheckContext *ctx);
static void report_corruption(HeapCheckContext *ctx, char *msg);
static TupleDesc verify_heapam_tupdesc(void);
memset(&ctx, 0, sizeof(HeapCheckContext));
ctx.cached_xid = InvalidTransactionId;
+ /*
+ * Any xmin newer than the xmin of our snapshot can't become all-visible
+ * while we're running.
+ */
+ ctx.safe_xmin = GetTransactionSnapshot()->xmin;
+
/*
* If we report corruption when not examining some individual attribute,
* we need attnum to be reported as NULL. Set that up before any
}
/*
- * Check for tuple header corruption and tuple visibility.
- *
- * Since we do not hold a snapshot, tuple visibility is not a question of
- * whether we should be able to see the tuple relative to any particular
- * snapshot, but rather a question of whether it is safe and reasonable to
- * check the tuple attributes.
+ * Check for tuple header corruption.
*
* Some kinds of corruption make it unsafe to check the tuple attributes, for
* example when the line pointer refers to a range of bytes outside the page.
- * In such cases, we return false (not visible) after recording appropriate
+ * In such cases, we return false (not checkable) after recording appropriate
* corruption messages.
*
* Some other kinds of tuple header corruption confuse the question of where
*
* Other kinds of tuple header corruption do not bear on the question of
* whether the tuple attributes can be checked, so we record corruption
- * messages for them but do not base our visibility determination on them. (In
- * other words, we do not return false merely because we detected them.)
- *
- * For visibility determination not specifically related to corruption, what we
- * want to know is if a tuple is potentially visible to any running
- * transaction. If you are tempted to replace this function's visibility logic
- * with a call to another visibility checking function, keep in mind that this
- * function does not update hint bits, as it seems imprudent to write hint bits
- * (or anything at all) to a table during a corruption check. Nor does this
- * function bother classifying tuple visibility beyond a boolean visible vs.
- * not visible.
- *
- * The caller should already have checked that xmin and xmax are not out of
- * bounds for the relation.
+ * messages for them but we do not return false merely because we detected
+ * them.
*
- * Returns whether the tuple is both visible and sufficiently sensible to
- * undergo attribute checks.
+ * Returns whether the tuple is sufficiently sensible to undergo visibility and
+ * attribute checks.
*/
static bool
-check_tuple_header_and_visibilty(HeapTupleHeader tuphdr, HeapCheckContext *ctx)
+check_tuple_header(HeapCheckContext *ctx)
{
+ HeapTupleHeader tuphdr = ctx->tuphdr;
uint16 infomask = tuphdr->t_infomask;
- bool header_garbled = false;
+ bool result = true;
unsigned expected_hoff;
if (ctx->tuphdr->t_hoff > ctx->lp_len)
report_corruption(ctx,
psprintf("data begins at offset %u beyond the tuple length %u",
ctx->tuphdr->t_hoff, ctx->lp_len));
- header_garbled = true;
+ result = false;
}
if ((ctx->tuphdr->t_infomask & HEAP_XMAX_COMMITTED) &&
pstrdup("multixact should not be marked committed"));
/*
- * This condition is clearly wrong, but we do not consider the header
- * garbled, because we don't rely on this property for determining if
- * the tuple is visible or for interpreting other relevant header
+ * This condition is clearly wrong, but it's not enough to justify
+ * skipping further checks, because we don't rely on this to determine
+ * whether the tuple is visible or to interpret other relevant header
* fields.
*/
}
report_corruption(ctx,
psprintf("tuple data should begin at byte %u, but actually begins at byte %u (%u attributes, no nulls)",
expected_hoff, ctx->tuphdr->t_hoff, ctx->natts));
- header_garbled = true;
+ result = false;
}
- if (header_garbled)
- return false; /* checking of this tuple should not continue */
+ return result;
+}
+
+/*
+ * Checks tuple visibility so we know which further checks are safe to
+ * perform.
+ *
+ * If a tuple could have been inserted by a transaction that also added a
+ * column to the table, but which ultimately did not commit, or which has not
+ * yet committed, then the table's current TupleDesc might differ from the one
+ * used to construct this tuple, so we must not check it.
+ *
+ * As a special case, if our own transaction inserted the tuple, even if we
+ * added a column to the table, our TupleDesc should match. We could check the
+ * tuple, but choose not to do so.
+ *
+ * If a tuple has been updated or deleted, we can still read the old tuple for
+ * corruption checking purposes, as long as we are careful about concurrent
+ * vacuums. The main table tuple itself cannot be vacuumed away because we
+ * hold a buffer lock on the page, but if the deleting transaction is older
+ * than our transaction snapshot's xmin, then vacuum could remove the toast at
+ * any time, so we must not try to follow TOAST pointers.
+ *
+ * If xmin or xmax values are older than can be checked against clog, or appear
+ * to be in the future (possibly due to wrap-around), then we cannot make a
+ * determination about the visibility of the tuple, so we skip further checks.
+ *
+ * Returns true if the tuple itself should be checked, false otherwise. Sets
+ * ctx->tuple_could_be_pruned if the tuple -- and thus also any associated
+ * TOAST tuples -- are eligible for pruning.
+ */
+static bool
+check_tuple_visibility(HeapCheckContext *ctx)
+{
+ TransactionId xmin;
+ TransactionId xvac;
+ TransactionId xmax;
+ XidCommitStatus xmin_status;
+ XidCommitStatus xvac_status;
+ XidCommitStatus xmax_status;
+ HeapTupleHeader tuphdr = ctx->tuphdr;
+
+ ctx->tuple_could_be_pruned = true; /* have not yet proven otherwise */
+
+ /* If xmin is normal, it should be within valid range */
+ xmin = HeapTupleHeaderGetXmin(tuphdr);
+ switch (get_xid_status(xmin, ctx, &xmin_status))
+ {
+ case XID_INVALID:
+ case XID_BOUNDS_OK:
+ break;
+ case XID_IN_FUTURE:
+ report_corruption(ctx,
+ psprintf("xmin %u equals or exceeds next valid transaction ID %u:%u",
+ xmin,
+ EpochFromFullTransactionId(ctx->next_fxid),
+ XidFromFullTransactionId(ctx->next_fxid)));
+ return false;
+ case XID_PRECEDES_CLUSTERMIN:
+ report_corruption(ctx,
+ psprintf("xmin %u precedes oldest valid transaction ID %u:%u",
+ xmin,
+ EpochFromFullTransactionId(ctx->oldest_fxid),
+ XidFromFullTransactionId(ctx->oldest_fxid)));
+ return false;
+ case XID_PRECEDES_RELMIN:
+ report_corruption(ctx,
+ psprintf("xmin %u precedes relation freeze threshold %u:%u",
+ xmin,
+ EpochFromFullTransactionId(ctx->relfrozenfxid),
+ XidFromFullTransactionId(ctx->relfrozenfxid)));
+ return false;
+ }
/*
- * Ok, we can examine the header for tuple visibility purposes, though we
- * still need to be careful about a few remaining types of header
- * corruption. This logic roughly follows that of
- * HeapTupleSatisfiesVacuum. Where possible the comments indicate which
- * HTSV_Result we think that function might return for this tuple.
+ * Has inserting transaction committed?
*/
if (!HeapTupleHeaderXminCommitted(tuphdr))
{
- TransactionId raw_xmin = HeapTupleHeaderGetRawXmin(tuphdr);
-
if (HeapTupleHeaderXminInvalid(tuphdr))
- return false; /* HEAPTUPLE_DEAD */
+ return false; /* inserter aborted, don't check */
/* Used by pre-9.0 binary upgrades */
- else if (infomask & HEAP_MOVED_OFF ||
- infomask & HEAP_MOVED_IN)
+ else if (tuphdr->t_infomask & HEAP_MOVED_OFF)
{
- XidCommitStatus status;
- TransactionId xvac = HeapTupleHeaderGetXvac(tuphdr);
+ xvac = HeapTupleHeaderGetXvac(tuphdr);
- switch (get_xid_status(xvac, ctx, &status))
+ switch (get_xid_status(xvac, ctx, &xvac_status))
{
case XID_INVALID:
report_corruption(ctx,
- pstrdup("old-style VACUUM FULL transaction ID is invalid"));
- return false; /* corrupt */
+ pstrdup("old-style VACUUM FULL transaction ID for moved off tuple is invalid"));
+ return false;
case XID_IN_FUTURE:
report_corruption(ctx,
- psprintf("old-style VACUUM FULL transaction ID %u equals or exceeds next valid transaction ID %u:%u",
+ psprintf("old-style VACUUM FULL transaction ID %u for moved off tuple equals or exceeds next valid transaction ID %u:%u",
xvac,
EpochFromFullTransactionId(ctx->next_fxid),
XidFromFullTransactionId(ctx->next_fxid)));
- return false; /* corrupt */
+ return false;
case XID_PRECEDES_RELMIN:
report_corruption(ctx,
- psprintf("old-style VACUUM FULL transaction ID %u precedes relation freeze threshold %u:%u",
+ psprintf("old-style VACUUM FULL transaction ID %u for moved off tuple precedes relation freeze threshold %u:%u",
xvac,
EpochFromFullTransactionId(ctx->relfrozenfxid),
XidFromFullTransactionId(ctx->relfrozenfxid)));
- return false; /* corrupt */
- break;
+ return false;
case XID_PRECEDES_CLUSTERMIN:
report_corruption(ctx,
- psprintf("old-style VACUUM FULL transaction ID %u precedes oldest valid transaction ID %u:%u",
+ psprintf("old-style VACUUM FULL transaction ID %u for moved off tuple precedes oldest valid transaction ID %u:%u",
xvac,
EpochFromFullTransactionId(ctx->oldest_fxid),
XidFromFullTransactionId(ctx->oldest_fxid)));
- return false; /* corrupt */
- break;
+ return false;
case XID_BOUNDS_OK:
- switch (status)
- {
- case XID_IN_PROGRESS:
- return true; /* HEAPTUPLE_DELETE_IN_PROGRESS */
- case XID_COMMITTED:
- case XID_ABORTED:
- return false; /* HEAPTUPLE_DEAD */
- }
+ break;
+ }
+
+ switch (xvac_status)
+ {
+ case XID_IS_CURRENT_XID:
+ report_corruption(ctx,
+ psprintf("old-style VACUUM FULL transaction ID %u for moved off tuple matches our current transaction ID",
+ xvac));
+ return false;
+ case XID_IN_PROGRESS:
+ report_corruption(ctx,
+ psprintf("old-style VACUUM FULL transaction ID %u for moved off tuple appears to be in progress",
+ xvac));
+ return false;
+
+ case XID_COMMITTED:
+ /*
+ * The tuple is dead, because the xvac transaction moved
+ * it off and comitted. It's checkable, but also prunable.
+ */
+ return true;
+
+ case XID_ABORTED:
+ /*
+ * The original xmin must have committed, because the xvac
+ * transaction tried to move it later. Since xvac is
+ * aborted, whether it's still alive now depends on the
+ * status of xmax.
+ */
+ break;
}
}
- else
+ /* Used by pre-9.0 binary upgrades */
+ else if (tuphdr->t_infomask & HEAP_MOVED_IN)
{
- XidCommitStatus status;
+ xvac = HeapTupleHeaderGetXvac(tuphdr);
- switch (get_xid_status(raw_xmin, ctx, &status))
+ switch (get_xid_status(xvac, ctx, &xvac_status))
{
case XID_INVALID:
report_corruption(ctx,
- pstrdup("raw xmin is invalid"));
+ pstrdup("old-style VACUUM FULL transaction ID for moved in tuple is invalid"));
return false;
case XID_IN_FUTURE:
report_corruption(ctx,
- psprintf("raw xmin %u equals or exceeds next valid transaction ID %u:%u",
- raw_xmin,
+ psprintf("old-style VACUUM FULL transaction ID %u for moved in tuple equals or exceeds next valid transaction ID %u:%u",
+ xvac,
EpochFromFullTransactionId(ctx->next_fxid),
XidFromFullTransactionId(ctx->next_fxid)));
- return false; /* corrupt */
+ return false;
case XID_PRECEDES_RELMIN:
report_corruption(ctx,
- psprintf("raw xmin %u precedes relation freeze threshold %u:%u",
- raw_xmin,
+ psprintf("old-style VACUUM FULL transaction ID %u for moved in tuple precedes relation freeze threshold %u:%u",
+ xvac,
EpochFromFullTransactionId(ctx->relfrozenfxid),
XidFromFullTransactionId(ctx->relfrozenfxid)));
- return false; /* corrupt */
+ return false;
case XID_PRECEDES_CLUSTERMIN:
report_corruption(ctx,
- psprintf("raw xmin %u precedes oldest valid transaction ID %u:%u",
- raw_xmin,
+ psprintf("old-style VACUUM FULL transaction ID %u for moved in tuple precedes oldest valid transaction ID %u:%u",
+ xvac,
EpochFromFullTransactionId(ctx->oldest_fxid),
XidFromFullTransactionId(ctx->oldest_fxid)));
- return false; /* corrupt */
+ return false;
case XID_BOUNDS_OK:
- switch (status)
- {
- case XID_COMMITTED:
- break;
- case XID_IN_PROGRESS:
- return true; /* insert or delete in progress */
- case XID_ABORTED:
- return false; /* HEAPTUPLE_DEAD */
- }
+ break;
}
+
+ switch (xvac_status)
+ {
+ case XID_IS_CURRENT_XID:
+ report_corruption(ctx,
+ psprintf("old-style VACUUM FULL transaction ID %u for moved in tuple matches our current transaction ID",
+ xvac));
+ return false;
+ case XID_IN_PROGRESS:
+ report_corruption(ctx,
+ psprintf("old-style VACUUM FULL transaction ID %u for moved in tuple appears to be in progress",
+ xvac));
+ return false;
+
+ case XID_COMMITTED:
+ /*
+ * The original xmin must have committed, because the xvac
+ * transaction moved it later. Whether it's still alive
+ * now depends on the status of xmax.
+ */
+ break;
+
+ case XID_ABORTED:
+ /*
+ * The tuple is dead, because the xvac transaction moved
+ * it off and comitted. It's checkable, but also prunable.
+ */
+ return true;
+ }
+ }
+ else if (xmin_status != XID_COMMITTED)
+ {
+ /*
+ * Inserting transaction is not in progress, and not committed, so
+ * it might have changed the TupleDesc in ways we don't know about.
+ * Thus, don't try to check the tuple structure.
+ *
+ * If xmin_status happens to be XID_IS_CURRENT_XID, then in theory
+ * any such DDL changes ought to be visible to us, so perhaps
+ * we could check anyway in that case. But, for now, let's be
+ * conservate and treat this like any other uncommitted insert.
+ */
+ return false;
}
}
- if (!(infomask & HEAP_XMAX_INVALID) && !HEAP_XMAX_IS_LOCKED_ONLY(infomask))
+ /*
+ * Okay, the inserter committed, so it was good at some point. Now what
+ * about the deleting transaction?
+ */
+
+ if (tuphdr->t_infomask & HEAP_XMAX_IS_MULTI)
{
- if (infomask & HEAP_XMAX_IS_MULTI)
+ /*
+ * xmax is a multixact, so sanity-check the MXID. Note that we do this
+ * prior to checking for HEAP_XMAX_INVALID or HEAP_XMAX_IS_LOCKED_ONLY.
+ * This might therefore complain about things that wouldn't actually
+ * be a problem during a normal scan, but eventually we're going to
+ * have to freeze, and that process will ignore hint bits.
+ *
+ * Even if the MXID is out of range, we still know that the original
+ * insert committed, so we can check the tuple itself. However, we
+ * can't rule out the possibility that this tuple is dead, so don't
+ * clear ctx->tuple_could_be_pruned. Possibly we should go ahead and
+ * clear that flag anyway if HEAP_XMAX_INVALID is set or if
+ * HEAP_XMAX_IS_LOCKED_ONLY is true, but for now we err on the side
+ * of avoiding possibly-bogus complaints about missing TOAST entries.
+ */
+ xmax = HeapTupleHeaderGetRawXmax(tuphdr);
+ switch (check_mxid_valid_in_rel(xmax, ctx))
{
- XidCommitStatus status;
- TransactionId xmax = HeapTupleGetUpdateXid(tuphdr);
+ case XID_INVALID:
+ report_corruption(ctx,
+ pstrdup("multitransaction ID is invalid"));
+ return true;
+ case XID_PRECEDES_RELMIN:
+ report_corruption(ctx,
+ psprintf("multitransaction ID %u precedes relation minimum multitransaction ID threshold %u",
+ xmax, ctx->relminmxid));
+ return true;
+ case XID_PRECEDES_CLUSTERMIN:
+ report_corruption(ctx,
+ psprintf("multitransaction ID %u precedes oldest valid multitransaction ID threshold %u",
+ xmax, ctx->oldest_mxact));
+ return true;
+ case XID_IN_FUTURE:
+ report_corruption(ctx,
+ psprintf("multitransaction ID %u equals or exceeds next valid multitransaction ID %u",
+ xmax,
+ ctx->next_mxact));
+ return true;
+ case XID_BOUNDS_OK:
+ break;
+ }
+ }
- switch (get_xid_status(xmax, ctx, &status))
- {
- /* not LOCKED_ONLY, so it has to have an xmax */
- case XID_INVALID:
- report_corruption(ctx,
- pstrdup("xmax is invalid"));
- return false; /* corrupt */
- case XID_IN_FUTURE:
- report_corruption(ctx,
- psprintf("xmax %u equals or exceeds next valid transaction ID %u:%u",
- xmax,
- EpochFromFullTransactionId(ctx->next_fxid),
- XidFromFullTransactionId(ctx->next_fxid)));
- return false; /* corrupt */
- case XID_PRECEDES_RELMIN:
- report_corruption(ctx,
- psprintf("xmax %u precedes relation freeze threshold %u:%u",
- xmax,
- EpochFromFullTransactionId(ctx->relfrozenfxid),
- XidFromFullTransactionId(ctx->relfrozenfxid)));
- return false; /* corrupt */
- case XID_PRECEDES_CLUSTERMIN:
- report_corruption(ctx,
- psprintf("xmax %u precedes oldest valid transaction ID %u:%u",
- xmax,
- EpochFromFullTransactionId(ctx->oldest_fxid),
- XidFromFullTransactionId(ctx->oldest_fxid)));
- return false; /* corrupt */
- case XID_BOUNDS_OK:
- switch (status)
- {
- case XID_IN_PROGRESS:
- return true; /* HEAPTUPLE_DELETE_IN_PROGRESS */
- case XID_COMMITTED:
- case XID_ABORTED:
- return false; /* HEAPTUPLE_RECENTLY_DEAD or
- * HEAPTUPLE_DEAD */
- }
- }
+ if (tuphdr->t_infomask & HEAP_XMAX_INVALID)
+ {
+ /*
+ * This tuple is live. A concurrently running transaction could
+ * delete it before we get around to checking the toast, but any such
+ * running transaction is surely not less than our safe_xmin, so the
+ * toast cannot be vacuumed out from under us.
+ */
+ ctx->tuple_could_be_pruned = false;
+ return true;
+ }
- /* Ok, the tuple is live */
+ if (HEAP_XMAX_IS_LOCKED_ONLY(tuphdr->t_infomask))
+ {
+ /*
+ * "Deleting" xact really only locked it, so the tuple is live in any
+ * case. As above, a concurrently running transaction could delete
+ * it, but it cannot be vacuumed out from under us.
+ */
+ ctx->tuple_could_be_pruned = false;
+ return true;
+ }
+
+ if (tuphdr->t_infomask & HEAP_XMAX_IS_MULTI)
+ {
+ /*
+ * We already checked above that this multixact is within limits for
+ * this table. Now check the update xid from this multixact.
+ */
+ xmax = HeapTupleGetUpdateXid(tuphdr);
+ switch (get_xid_status(xmax, ctx, &xmax_status))
+ {
+ case XID_INVALID:
+ /* not LOCKED_ONLY, so it has to have an xmax */
+ report_corruption(ctx,
+ pstrdup("update xid is invalid"));
+ return true;
+ case XID_IN_FUTURE:
+ report_corruption(ctx,
+ psprintf("update xid %u equals or exceeds next valid transaction ID %u:%u",
+ xmax,
+ EpochFromFullTransactionId(ctx->next_fxid),
+ XidFromFullTransactionId(ctx->next_fxid)));
+ return true;
+ case XID_PRECEDES_RELMIN:
+ report_corruption(ctx,
+ psprintf("update xid %u precedes relation freeze threshold %u:%u",
+ xmax,
+ EpochFromFullTransactionId(ctx->relfrozenfxid),
+ XidFromFullTransactionId(ctx->relfrozenfxid)));
+ return true;
+ case XID_PRECEDES_CLUSTERMIN:
+ report_corruption(ctx,
+ psprintf("update xid %u precedes oldest valid transaction ID %u:%u",
+ xmax,
+ EpochFromFullTransactionId(ctx->oldest_fxid),
+ XidFromFullTransactionId(ctx->oldest_fxid)));
+ return true;
+ case XID_BOUNDS_OK:
+ break;
}
- else if (!(infomask & HEAP_XMAX_COMMITTED))
- return true; /* HEAPTUPLE_DELETE_IN_PROGRESS or
- * HEAPTUPLE_LIVE */
- else
- return false; /* HEAPTUPLE_RECENTLY_DEAD or HEAPTUPLE_DEAD */
+
+ switch (xmax_status)
+ {
+ case XID_IS_CURRENT_XID:
+ case XID_IN_PROGRESS:
+
+ /*
+ * The delete is in progress, so it cannot be visible to our
+ * snapshot.
+ */
+ ctx->tuple_could_be_pruned = false;
+ break;
+ case XID_COMMITTED:
+
+ /*
+ * The delete committed. Whether the toast can be vacuumed
+ * away depends on how old the deleting transaction is.
+ */
+ ctx->tuple_could_be_pruned = TransactionIdPrecedes(xmax,
+ ctx->safe_xmin);
+ break;
+ case XID_ABORTED:
+ /*
+ * The delete aborted or crashed. The tuple is still live.
+ */
+ ctx->tuple_could_be_pruned = false;
+ break;
+ }
+
+ /* Tuple itself is checkable even if it's dead. */
+ return true;
+ }
+
+ /* xmax is an XID, not a MXID. Sanity check it. */
+ xmax = HeapTupleHeaderGetRawXmax(tuphdr);
+ switch (get_xid_status(xmax, ctx, &xmax_status))
+ {
+ case XID_IN_FUTURE:
+ report_corruption(ctx,
+ psprintf("xmax %u equals or exceeds next valid transaction ID %u:%u",
+ xmax,
+ EpochFromFullTransactionId(ctx->next_fxid),
+ XidFromFullTransactionId(ctx->next_fxid)));
+ return false; /* corrupt */
+ case XID_PRECEDES_RELMIN:
+ report_corruption(ctx,
+ psprintf("xmax %u precedes relation freeze threshold %u:%u",
+ xmax,
+ EpochFromFullTransactionId(ctx->relfrozenfxid),
+ XidFromFullTransactionId(ctx->relfrozenfxid)));
+ return false; /* corrupt */
+ case XID_PRECEDES_CLUSTERMIN:
+ report_corruption(ctx,
+ psprintf("xmax %u precedes oldest valid transaction ID %u:%u",
+ xmax,
+ EpochFromFullTransactionId(ctx->oldest_fxid),
+ XidFromFullTransactionId(ctx->oldest_fxid)));
+ return false; /* corrupt */
+ case XID_BOUNDS_OK:
+ case XID_INVALID:
+ break;
}
- return true; /* not dead */
+
+ /*
+ * Whether the toast can be vacuumed away depends on how old the deleting
+ * transaction is.
+ */
+ switch (xmax_status)
+ {
+ case XID_IS_CURRENT_XID:
+ case XID_IN_PROGRESS:
+
+ /*
+ * The delete is in progress, so it cannot be visible to our
+ * snapshot.
+ */
+ ctx->tuple_could_be_pruned = false;
+ break;
+
+ case XID_COMMITTED:
+ /*
+ * The delete committed. Whether the toast can be vacuumed away
+ * depends on how old the deleting transaction is.
+ */
+ ctx->tuple_could_be_pruned = TransactionIdPrecedes(xmax,
+ ctx->safe_xmin);
+ break;
+
+ case XID_ABORTED:
+ /*
+ * The delete aborted or crashed. The tuple is still live.
+ */
+ ctx->tuple_could_be_pruned = false;
+ break;
+ }
+
+ /* Tuple itself is checkable even if it's dead. */
+ return true;
}
+
/*
* Check the current toast tuple against the state tracked in ctx, recording
* any corruption found in ctx->tupstore.
* corrupt to continue checking, or if the tuple is not visible to anyone,
* we cannot continue with other checks.
*/
- if (!check_tuple_header_and_visibilty(ctx->tuphdr, ctx))
+ if (!check_tuple_header(ctx))
+ return;
+
+ if (!check_tuple_visibility(ctx))
return;
/*
if (FullTransactionIdPrecedesOrEquals(clog_horizon, fxid))
{
if (TransactionIdIsCurrentTransactionId(xid))
+ *status = XID_IS_CURRENT_XID;
+ else if (TransactionIdIsInProgress(xid))
*status = XID_IN_PROGRESS;
else if (TransactionIdDidCommit(xid))
*status = XID_COMMITTED;
- else if (TransactionIdDidAbort(xid))
- *status = XID_ABORTED;
else
- *status = XID_IN_PROGRESS;
+ *status = XID_ABORTED;
}
LWLockRelease(XactTruncationLock);
ctx->cached_xid = xid;
projects / users / rhaas / postgres.git / commitdiff