"\"%s/pg_resetxlog\" -f -e %u \"%s\"",
new_cluster.bindir, old_cluster.controldata.chkpnt_nxtepoch,
new_cluster.pgdata);
+ /* must reset commit timestamp limits also */
+ exec_prog(UTILITY_LOG_FILE, NULL, true,
+ "\"%s/pg_resetxlog\" -f -c %u,%u \"%s\"",
+ new_cluster.bindir,
+ old_cluster.controldata.chkpnt_nxtxid,
+ old_cluster.controldata.chkpnt_nxtxid,
+ new_cluster.pgdata);
check_ok();
/*
#include "access/brin_xlog.h"
#include "access/clog.h"
+#include "access/commit_ts.h"
#include "access/gin.h"
#include "access/gist_private.h"
#include "access/hash.h"
</listitem>
</varlistentry>
+ <varlistentry id="guc-track-commit-timestamp" xreflabel="track_commit_timestamp">
+ <term><varname>track_commit_timestamp</varname> (<type>bool</type>)</term>
+ <indexterm>
+ <primary><varname>track_commit_timestamp</> configuration parameter</primary>
+ </indexterm>
+ <listitem>
+ <para>
+ Record commit time of transactions. This parameter
+ can only be set in <filename>postgresql.conf</> file or on the server
+ command line. The default value is <literal>off</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</sect2>
For example <literal>10:20:10,14,15</literal> means
<literal>xmin=10, xmax=20, xip_list=10, 14, 15</literal>.
</para>
+
+ <para>
+ The functions shown in <xref linkend="functions-commit-timestamp">
+ provide information about transactions that have been already committed.
+ These functions mainly provide information about when the transactions
+ were committed. They only provide useful data when
+ <xref linkend="guc-track-commit-timestamp"> configuration option is enabled
+ and only for transactions that were committed after it was enabled.
+ </para>
+
+ <table id="functions-commit-timestamp">
+ <title>Committed transaction information</title>
+ <tgroup cols="3">
+ <thead>
+ <row><entry>Name</entry> <entry>Return Type</entry> <entry>Description</entry></row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry>
+ <indexterm><primary>pg_xact_commit_timestamp</primary></indexterm>
+ <literal><function>pg_xact_commit_timestamp(<parameter>xid</parameter>)</function></literal>
+ </entry>
+ <entry><type>timestamp with time zone</type></entry>
+ <entry>get commit timestamp of a transaction</entry>
+ </row>
+
+ <row>
+ <entry>
+ <indexterm><primary>pg_last_committed_xact</primary></indexterm>
+ <literal><function>pg_last_committed_xact()</function></literal>
+ </entry>
+ <entry><parameter>xid</> <type>xid</>, <parameter>timestamp</> <type>timestamp with time zone</></entry>
+ <entry>get transaction ID and commit timestamp of latest committed transaction</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
</sect1>
<sect1 id="functions-admin">
<refsynopsisdiv>
<cmdsynopsis>
<command>pg_resetxlog</command>
+ <arg choice="opt"><option>-c</option> <replaceable class="parameter">xid</replaceable>,<replaceable class="parameter">xid</replaceable></arg>
<arg choice="opt"><option>-f</option></arg>
<arg choice="opt"><option>-n</option></arg>
<arg choice="opt"><option>-o</option> <replaceable class="parameter">oid</replaceable></arg>
<para>
The <option>-o</>, <option>-x</>, <option>-e</>,
<option>-m</>, <option>-O</>,
+ <option>-c</>
and <option>-l</>
options allow the next OID, next transaction ID, next transaction ID's
- epoch, next and oldest multitransaction ID, next multitransaction offset, and WAL
+ epoch, next and oldest multitransaction ID, next multitransaction offset,
+ oldest and newest transaction IDs for which the commit time can be retrieved,
+ and WAL
starting address values to be set manually. These are only needed when
<command>pg_resetxlog</command> is unable to determine appropriate values
by reading <filename>pg_control</>. Safe values can be determined as
</para>
</listitem>
+ <listitem>
+ <para>
+ A safe value for the oldest transaction ID for which the commit time can
+ be retrieved (first part of <option>-c</>) can be determined by looking
+ for the numerically smallest file name in the directory
+ <filename>pg_committs</> under the data directory. Conversely, a safe
+ value for the newest transaction ID for which the commit time can be
+ retrieved (second part of <option>-c</>) can be determined by looking for
+ the numerically greatest file name in the same directory. As above, the
+ file names are in hexadecimal.
+ </para>
+ </listitem>
+
<listitem>
<para>
The WAL starting address (<option>-l</>) should be
<structname>pg_database</></entry>
</row>
+<row>
+ <entry><filename>pg_commit_ts</></entry>
+ <entry>Subdirectory containing transaction commit timestamp data</entry>
+</row>
+
<row>
<entry><filename>pg_clog</></entry>
<entry>Subdirectory containing transaction commit status data</entry>
top_builddir = ../../../..
include $(top_builddir)/src/Makefile.global
-OBJS = brindesc.o clogdesc.o dbasedesc.o gindesc.o gistdesc.o \
+OBJS = brindesc.o clogdesc.o committsdesc.o dbasedesc.o gindesc.o gistdesc.o \
hashdesc.o heapdesc.o \
mxactdesc.o nbtdesc.o relmapdesc.o seqdesc.o smgrdesc.o spgdesc.o \
standbydesc.o tblspcdesc.o xactdesc.o xlogdesc.o
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * committsdesc.c
+ * rmgr descriptor routines for access/transam/commit_ts.c
+ *
+ * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/access/rmgrdesc/committsdesc.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/commit_ts.h"
+#include "utils/timestamp.h"
+
+
+void
+commit_ts_desc(StringInfo buf, XLogReaderState *record)
+{
+ char *rec = XLogRecGetData(record);
+ uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
+
+ if (info == COMMIT_TS_ZEROPAGE)
+ {
+ int pageno;
+
+ memcpy(&pageno, rec, sizeof(int));
+ appendStringInfo(buf, "%d", pageno);
+ }
+ else if (info == COMMIT_TS_TRUNCATE)
+ {
+ int pageno;
+
+ memcpy(&pageno, rec, sizeof(int));
+ appendStringInfo(buf, "%d", pageno);
+ }
+ else if (info == COMMIT_TS_SETTS)
+ {
+ xl_commit_ts_set *xlrec = (xl_commit_ts_set *) rec;
+ int nsubxids;
+
+ appendStringInfo(buf, "set %s/%d for: %u",
+ timestamptz_to_str(xlrec->timestamp),
+ xlrec->nodeid,
+ xlrec->mainxid);
+ nsubxids = ((XLogRecGetDataLen(record) - SizeOfCommitTsSet) /
+ sizeof(TransactionId));
+ if (nsubxids > 0)
+ {
+ int i;
+ TransactionId *subxids;
+
+ subxids = palloc(sizeof(TransactionId) * nsubxids);
+ memcpy(subxids,
+ XLogRecGetData(record) + SizeOfCommitTsSet,
+ sizeof(TransactionId) * nsubxids);
+ for (i = 0; i < nsubxids; i++)
+ appendStringInfo(buf, ", %u", subxids[i]);
+ pfree(subxids);
+ }
+ }
+}
+
+const char *
+commit_ts_identify(uint8 info)
+{
+ switch (info)
+ {
+ case COMMIT_TS_ZEROPAGE:
+ return "ZEROPAGE";
+ case COMMIT_TS_TRUNCATE:
+ return "TRUNCATE";
+ case COMMIT_TS_SETTS:
+ return "SETTS";
+ default:
+ return NULL;
+ }
+}
appendStringInfo(buf, "redo %X/%X; "
"tli %u; prev tli %u; fpw %s; xid %u/%u; oid %u; multi %u; offset %u; "
"oldest xid %u in DB %u; oldest multi %u in DB %u; "
+ "oldest/newest commit timestamp xid: %u/%u; "
"oldest running xid %u; %s",
(uint32) (checkpoint->redo >> 32), (uint32) checkpoint->redo,
checkpoint->ThisTimeLineID,
checkpoint->oldestXidDB,
checkpoint->oldestMulti,
checkpoint->oldestMultiDB,
+ checkpoint->oldestCommitTs,
+ checkpoint->newestCommitTs,
checkpoint->oldestActiveXid,
(info == XLOG_CHECKPOINT_SHUTDOWN) ? "shutdown" : "online");
}
top_builddir = ../../../..
include $(top_builddir)/src/Makefile.global
-OBJS = clog.o transam.o varsup.o xact.o rmgr.o slru.o subtrans.o multixact.o \
- timeline.o twophase.o twophase_rmgr.o xlog.o xlogarchive.o xlogfuncs.o \
+OBJS = clog.o commit_ts.o multixact.o rmgr.o slru.o subtrans.o \
+ timeline.o transam.o twophase.o twophase_rmgr.o varsup.o \
+ xact.o xlog.o xlogarchive.o xlogfuncs.o \
xloginsert.o xlogreader.o xlogutils.o
include $(top_srcdir)/src/backend/common.mk
Not all transactional behaviour is emulated, for example we do not insert
a transaction entry into the lock table, nor do we maintain the transaction
-stack in memory. Clog and multixact entries are made normally.
+stack in memory. Clog, multixact and commit_ts entries are made normally.
Subtrans is maintained during recovery but the details of the transaction
tree are ignored and all subtransactions reference the top-level TransactionId
directly. Since commit is atomic this provides correct lock wait behaviour
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * commit_ts.c
+ * PostgreSQL commit timestamp manager
+ *
+ * This module is a pg_clog-like system that stores the commit timestamp
+ * for each transaction.
+ *
+ * XLOG interactions: this module generates an XLOG record whenever a new
+ * CommitTs page is initialized to zeroes. Also, one XLOG record is
+ * generated for setting of values when the caller requests it; this allows
+ * us to support values coming from places other than transaction commit.
+ * Other writes of CommitTS come from recording of transaction commit in
+ * xact.c, which generates its own XLOG records for these events and will
+ * re-perform the status update on redo; so we need make no additional XLOG
+ * entry here.
+ *
+ * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/backend/access/transam/commit_ts.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/commit_ts.h"
+#include "access/htup_details.h"
+#include "access/slru.h"
+#include "access/transam.h"
+#include "catalog/pg_type.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "pg_trace.h"
+#include "utils/builtins.h"
+#include "utils/snapmgr.h"
+#include "utils/timestamp.h"
+
+/*
+ * Defines for CommitTs page sizes. A page is the same BLCKSZ as is used
+ * everywhere else in Postgres.
+ *
+ * Note: because TransactionIds are 32 bits and wrap around at 0xFFFFFFFF,
+ * CommitTs page numbering also wraps around at
+ * 0xFFFFFFFF/COMMIT_TS_XACTS_PER_PAGE, and CommitTs segment numbering at
+ * 0xFFFFFFFF/COMMIT_TS_XACTS_PER_PAGE/SLRU_PAGES_PER_SEGMENT. We need take no
+ * explicit notice of that fact in this module, except when comparing segment
+ * and page numbers in TruncateCommitTs (see CommitTsPagePrecedes).
+ */
+
+/*
+ * We need 8+4 bytes per xact. Note that enlarging this struct might mean
+ * the largest possible file name is more than 5 chars long; see
+ * SlruScanDirectory.
+ */
+typedef struct CommitTimestampEntry
+{
+ TimestampTz time;
+ CommitTsNodeId nodeid;
+} CommitTimestampEntry;
+
+#define SizeOfCommitTimestampEntry (offsetof(CommitTimestampEntry, nodeid) + \
+ sizeof(CommitTsNodeId))
+
+#define COMMIT_TS_XACTS_PER_PAGE \
+ (BLCKSZ / SizeOfCommitTimestampEntry)
+
+#define TransactionIdToCTsPage(xid) \
+ ((xid) / (TransactionId) COMMIT_TS_XACTS_PER_PAGE)
+#define TransactionIdToCTsEntry(xid) \
+ ((xid) % (TransactionId) COMMIT_TS_XACTS_PER_PAGE)
+
+/*
+ * Link to shared-memory data structures for CommitTs control
+ */
+static SlruCtlData CommitTsCtlData;
+
+#define CommitTsCtl (&CommitTsCtlData)
+
+/*
+ * We keep a cache of the last value set in shared memory. This is protected
+ * by CommitTsLock.
+ */
+typedef struct CommitTimestampShared
+{
+ TransactionId xidLastCommit;
+ CommitTimestampEntry dataLastCommit;
+} CommitTimestampShared;
+
+CommitTimestampShared *commitTsShared;
+
+
+/* GUC variable */
+bool track_commit_timestamp;
+
+static CommitTsNodeId default_node_id = InvalidCommitTsNodeId;
+
+static void SetXidCommitTsInPage(TransactionId xid, int nsubxids,
+ TransactionId *subxids, TimestampTz ts,
+ CommitTsNodeId nodeid, int pageno);
+static void TransactionIdSetCommitTs(TransactionId xid, TimestampTz ts,
+ CommitTsNodeId nodeid, int slotno);
+static int ZeroCommitTsPage(int pageno, bool writeXlog);
+static bool CommitTsPagePrecedes(int page1, int page2);
+static void WriteZeroPageXlogRec(int pageno);
+static void WriteTruncateXlogRec(int pageno);
+static void WriteSetTimestampXlogRec(TransactionId mainxid, int nsubxids,
+ TransactionId *subxids, TimestampTz timestamp,
+ CommitTsNodeId nodeid);
+
+
+/*
+ * CommitTsSetDefaultNodeId
+ *
+ * Set default nodeid for current backend.
+ */
+void
+CommitTsSetDefaultNodeId(CommitTsNodeId nodeid)
+{
+ default_node_id = nodeid;
+}
+
+/*
+ * CommitTsGetDefaultNodeId
+ *
+ * Set default nodeid for current backend.
+ */
+CommitTsNodeId
+CommitTsGetDefaultNodeId(void)
+{
+ return default_node_id;
+}
+
+/*
+ * TransactionTreeSetCommitTsData
+ *
+ * Record the final commit timestamp of transaction entries in the commit log
+ * for a transaction and its subtransaction tree, as efficiently as possible.
+ *
+ * xid is the top level transaction id.
+ *
+ * subxids is an array of xids of length nsubxids, representing subtransactions
+ * in the tree of xid. In various cases nsubxids may be zero.
+ * The reason why tracking just the parent xid commit timestamp is not enough
+ * is that the subtrans SLRU does not stay valid across crashes (it's not
+ * permanent) so we need to keep the information about them here. If the
+ * subtrans implementation changes in the future, we might want to revisit the
+ * decision of storing timestamp info for each subxid.
+ *
+ * The do_xlog parameter tells us whether to include a XLog record of this
+ * or not. Normal path through RecordTransactionCommit() will be related
+ * to a transaction commit XLog record, and so should pass "false" here.
+ * Other callers probably want to pass true, so that the given values persist
+ * in case of crashes.
+ */
+void
+TransactionTreeSetCommitTsData(TransactionId xid, int nsubxids,
+ TransactionId *subxids, TimestampTz timestamp,
+ CommitTsNodeId nodeid, bool do_xlog)
+{
+ int i;
+ TransactionId headxid;
+ TransactionId newestXact;
+
+ if (!track_commit_timestamp)
+ return;
+
+ /*
+ * Comply with the WAL-before-data rule: if caller specified it wants
+ * this value to be recorded in WAL, do so before touching the data.
+ */
+ if (do_xlog)
+ WriteSetTimestampXlogRec(xid, nsubxids, subxids, timestamp, nodeid);
+
+ /*
+ * Figure out the latest Xid in this batch: either the last subxid if
+ * there's any, otherwise the parent xid.
+ */
+ if (nsubxids > 0)
+ newestXact = subxids[nsubxids - 1];
+ else
+ newestXact = xid;
+
+ /*
+ * We split the xids to set the timestamp to in groups belonging to the
+ * same SLRU page; the first element in each such set is its head. The
+ * first group has the main XID as the head; subsequent sets use the
+ * first subxid not on the previous page as head. This way, we only have
+ * to lock/modify each SLRU page once.
+ */
+ for (i = 0, headxid = xid;;)
+ {
+ int pageno = TransactionIdToCTsPage(headxid);
+ int j;
+
+ for (j = i; j < nsubxids; j++)
+ {
+ if (TransactionIdToCTsPage(subxids[j]) != pageno)
+ break;
+ }
+ /* subxids[i..j] are on the same page as the head */
+
+ SetXidCommitTsInPage(headxid, j - i, subxids + i, timestamp, nodeid,
+ pageno);
+
+ /* if we wrote out all subxids, we're done. */
+ if (j + 1 >= nsubxids)
+ break;
+
+ /*
+ * Set the new head and skip over it, as well as over the subxids
+ * we just wrote.
+ */
+ headxid = subxids[j];
+ i += j - i + 1;
+ }
+
+ /* update the cached value in shared memory */
+ LWLockAcquire(CommitTsLock, LW_EXCLUSIVE);
+ commitTsShared->xidLastCommit = xid;
+ commitTsShared->dataLastCommit.time = timestamp;
+ commitTsShared->dataLastCommit.nodeid = nodeid;
+
+ /* and move forwards our endpoint, if needed */
+ if (TransactionIdPrecedes(ShmemVariableCache->newestCommitTs, newestXact))
+ ShmemVariableCache->newestCommitTs = newestXact;
+ LWLockRelease(CommitTsLock);
+}
+
+/*
+ * Record the commit timestamp of transaction entries in the commit log for all
+ * entries on a single page. Atomic only on this page.
+ */
+static void
+SetXidCommitTsInPage(TransactionId xid, int nsubxids,
+ TransactionId *subxids, TimestampTz ts,
+ CommitTsNodeId nodeid, int pageno)
+{
+ int slotno;
+ int i;
+
+ LWLockAcquire(CommitTsControlLock, LW_EXCLUSIVE);
+
+ slotno = SimpleLruReadPage(CommitTsCtl, pageno, true, xid);
+
+ TransactionIdSetCommitTs(xid, ts, nodeid, slotno);
+ for (i = 0; i < nsubxids; i++)
+ TransactionIdSetCommitTs(subxids[i], ts, nodeid, slotno);
+
+ CommitTsCtl->shared->page_dirty[slotno] = true;
+
+ LWLockRelease(CommitTsControlLock);
+}
+
+/*
+ * Sets the commit timestamp of a single transaction.
+ *
+ * Must be called with CommitTsControlLock held
+ */
+static void
+TransactionIdSetCommitTs(TransactionId xid, TimestampTz ts,
+ CommitTsNodeId nodeid, int slotno)
+{
+ int entryno = TransactionIdToCTsEntry(xid);
+ CommitTimestampEntry entry;
+
+ Assert(TransactionIdIsNormal(xid));
+
+ entry.time = ts;
+ entry.nodeid = nodeid;
+
+ memcpy(CommitTsCtl->shared->page_buffer[slotno] +
+ SizeOfCommitTimestampEntry * entryno,
+ &entry, SizeOfCommitTimestampEntry);
+}
+
+/*
+ * Interrogate the commit timestamp of a transaction.
+ *
+ * Return value indicates whether commit timestamp record was found for
+ * given xid.
+ */
+bool
+TransactionIdGetCommitTsData(TransactionId xid, TimestampTz *ts,
+ CommitTsNodeId *nodeid)
+{
+ int pageno = TransactionIdToCTsPage(xid);
+ int entryno = TransactionIdToCTsEntry(xid);
+ int slotno;
+ CommitTimestampEntry entry;
+ TransactionId oldestCommitTs;
+ TransactionId newestCommitTs;
+
+ /* Error if module not enabled */
+ if (!track_commit_timestamp)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("could not get commit timestamp data"),
+ errhint("Make sure the configuration parameter \"%s\" is set.",
+ "track_commit_timestamp")));
+
+ /* error if the given Xid doesn't normally commit */
+ if (!TransactionIdIsNormal(xid))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("cannot retrieve commit timestamp for transaction %u", xid)));
+
+ /*
+ * Return empty if the requested value is outside our valid range.
+ */
+ LWLockAcquire(CommitTsLock, LW_SHARED);
+ oldestCommitTs = ShmemVariableCache->oldestCommitTs;
+ newestCommitTs = ShmemVariableCache->newestCommitTs;
+ /* neither is invalid, or both are */
+ Assert(TransactionIdIsValid(oldestCommitTs) == TransactionIdIsValid(newestCommitTs));
+ LWLockRelease(CommitTsLock);
+
+ if (!TransactionIdIsValid(oldestCommitTs) ||
+ TransactionIdPrecedes(xid, oldestCommitTs) ||
+ TransactionIdPrecedes(newestCommitTs, xid))
+ {
+ if (ts)
+ *ts = 0;
+ if (nodeid)
+ *nodeid = InvalidCommitTsNodeId;
+ return false;
+ }
+
+ /*
+ * Use an unlocked atomic read on our cached value in shared memory; if
+ * it's a hit, acquire a lock and read the data, after verifying that it's
+ * still what we initially read. Otherwise, fall through to read from
+ * SLRU.
+ */
+ if (commitTsShared->xidLastCommit == xid)
+ {
+ LWLockAcquire(CommitTsLock, LW_SHARED);
+ if (commitTsShared->xidLastCommit == xid)
+ {
+ if (ts)
+ *ts = commitTsShared->dataLastCommit.time;
+ if (nodeid)
+ *nodeid = commitTsShared->dataLastCommit.nodeid;
+
+ LWLockRelease(CommitTsLock);
+ return *ts != 0;
+ }
+ LWLockRelease(CommitTsLock);
+ }
+
+ /* lock is acquired by SimpleLruReadPage_ReadOnly */
+ slotno = SimpleLruReadPage_ReadOnly(CommitTsCtl, pageno, xid);
+ memcpy(&entry,
+ CommitTsCtl->shared->page_buffer[slotno] +
+ SizeOfCommitTimestampEntry * entryno,
+ SizeOfCommitTimestampEntry);
+
+ if (ts)
+ *ts = entry.time;
+ if (nodeid)
+ *nodeid = entry.nodeid;
+
+ LWLockRelease(CommitTsControlLock);
+ return *ts != 0;
+}
+
+/*
+ * Return the Xid of the latest committed transaction. (As far as this module
+ * is concerned, anyway; it's up to the caller to ensure the value is useful
+ * for its purposes.)
+ *
+ * ts and extra are filled with the corresponding data; they can be passed
+ * as NULL if not wanted.
+ */
+TransactionId
+GetLatestCommitTsData(TimestampTz *ts, CommitTsNodeId *nodeid)
+{
+ TransactionId xid;
+
+ /* Error if module not enabled */
+ if (!track_commit_timestamp)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("could not get commit timestamp data"),
+ errhint("Make sure the configuration parameter \"%s\" is set.",
+ "track_commit_timestamp")));
+
+ LWLockAcquire(CommitTsLock, LW_SHARED);
+ xid = commitTsShared->xidLastCommit;
+ if (ts)
+ *ts = commitTsShared->dataLastCommit.time;
+ if (nodeid)
+ *nodeid = commitTsShared->dataLastCommit.nodeid;
+ LWLockRelease(CommitTsLock);
+
+ return xid;
+}
+
+/*
+ * SQL-callable wrapper to obtain commit time of a transaction
+ */
+Datum
+pg_xact_commit_timestamp(PG_FUNCTION_ARGS)
+{
+ TransactionId xid = PG_GETARG_UINT32(0);
+ TimestampTz ts;
+ bool found;
+
+ found = TransactionIdGetCommitTsData(xid, &ts, NULL);
+
+ if (!found)
+ PG_RETURN_NULL();
+
+ PG_RETURN_TIMESTAMPTZ(ts);
+}
+
+
+Datum
+pg_last_committed_xact(PG_FUNCTION_ARGS)
+{
+ TransactionId xid;
+ TimestampTz ts;
+ Datum values[2];
+ bool nulls[2];
+ TupleDesc tupdesc;
+ HeapTuple htup;
+
+ /* and construct a tuple with our data */
+ xid = GetLatestCommitTsData(&ts, NULL);
+
+ /*
+ * Construct a tuple descriptor for the result row. This must match this
+ * function's pg_proc entry!
+ */
+ tupdesc = CreateTemplateTupleDesc(2, false);
+ TupleDescInitEntry(tupdesc, (AttrNumber) 1, "xid",
+ XIDOID, -1, 0);
+ TupleDescInitEntry(tupdesc, (AttrNumber) 2, "timestamp",
+ TIMESTAMPTZOID, -1, 0);
+ tupdesc = BlessTupleDesc(tupdesc);
+
+ if (!TransactionIdIsNormal(xid))
+ {
+ memset(nulls, true, sizeof(nulls));
+ }
+ else
+ {
+ values[0] = TransactionIdGetDatum(xid);
+ nulls[0] = false;
+
+ values[1] = TimestampTzGetDatum(ts);
+ nulls[1] = false;
+ }
+
+ htup = heap_form_tuple(tupdesc, values, nulls);
+
+ PG_RETURN_DATUM(HeapTupleGetDatum(htup));
+}
+
+
+/*
+ * Number of shared CommitTS buffers.
+ *
+ * We use a very similar logic as for the number of CLOG buffers; see comments
+ * in CLOGShmemBuffers.
+ */
+Size
+CommitTsShmemBuffers(void)
+{
+ return Min(16, Max(4, NBuffers / 1024));
+}
+
+/*
+ * Shared memory sizing for CommitTs
+ */
+Size
+CommitTsShmemSize(void)
+{
+ return SimpleLruShmemSize(CommitTsShmemBuffers(), 0) +
+ sizeof(CommitTimestampShared);
+}
+
+/*
+ * Initialize CommitTs at system startup (postmaster start or standalone
+ * backend)
+ */
+void
+CommitTsShmemInit(void)
+{
+ bool found;
+
+ CommitTsCtl->PagePrecedes = CommitTsPagePrecedes;
+ SimpleLruInit(CommitTsCtl, "CommitTs Ctl", CommitTsShmemBuffers(), 0,
+ CommitTsControlLock, "pg_commit_ts");
+
+ commitTsShared = ShmemInitStruct("CommitTs shared",
+ sizeof(CommitTimestampShared),
+ &found);
+
+ if (!IsUnderPostmaster)
+ {
+ Assert(!found);
+
+ commitTsShared->xidLastCommit = InvalidTransactionId;
+ TIMESTAMP_NOBEGIN(commitTsShared->dataLastCommit.time);
+ commitTsShared->dataLastCommit.nodeid = InvalidCommitTsNodeId;
+ }
+ else
+ Assert(found);
+}
+
+/*
+ * This function must be called ONCE on system install.
+ *
+ * (The CommitTs directory is assumed to have been created by initdb, and
+ * CommitTsShmemInit must have been called already.)
+ */
+void
+BootStrapCommitTs(void)
+{
+ /*
+ * Nothing to do here at present, unlike most other SLRU modules; segments
+ * are created when the server is started with this module enabled.
+ * See StartupCommitTs.
+ */
+}
+
+/*
+ * Initialize (or reinitialize) a page of CommitTs to zeroes.
+ * If writeXlog is TRUE, also emit an XLOG record saying we did this.
+ *
+ * The page is not actually written, just set up in shared memory.
+ * The slot number of the new page is returned.
+ *
+ * Control lock must be held at entry, and will be held at exit.
+ */
+static int
+ZeroCommitTsPage(int pageno, bool writeXlog)
+{
+ int slotno;
+
+ slotno = SimpleLruZeroPage(CommitTsCtl, pageno);
+
+ if (writeXlog)
+ WriteZeroPageXlogRec(pageno);
+
+ return slotno;
+}
+
+/*
+ * This must be called ONCE during postmaster or standalone-backend startup,
+ * after StartupXLOG has initialized ShmemVariableCache->nextXid.
+ */
+void
+StartupCommitTs(void)
+{
+ TransactionId xid = ShmemVariableCache->nextXid;
+ int pageno = TransactionIdToCTsPage(xid);
+
+ LWLockAcquire(CommitTsControlLock, LW_EXCLUSIVE);
+
+ /*
+ * Initialize our idea of the latest page number.
+ */
+ CommitTsCtl->shared->latest_page_number = pageno;
+
+ LWLockRelease(CommitTsControlLock);
+}
+
+/*
+ * This must be called ONCE during postmaster or standalone-backend startup,
+ * when commit timestamp is enabled. Must be called after recovery has
+ * finished.
+ *
+ * This is in charge of creating the currently active segment, if it's not
+ * already there. The reason for this is that the server might have been
+ * running with this module disabled for a while and thus might have skipped
+ * the normal creation point.
+ */
+void
+CompleteCommitTsInitialization(void)
+{
+ TransactionId xid = ShmemVariableCache->nextXid;
+ int pageno = TransactionIdToCTsPage(xid);
+
+ /*
+ * Re-Initialize our idea of the latest page number.
+ */
+ LWLockAcquire(CommitTsControlLock, LW_EXCLUSIVE);
+ CommitTsCtl->shared->latest_page_number = pageno;
+ LWLockRelease(CommitTsControlLock);
+
+ /*
+ * If this module is not currently enabled, make sure we don't hand back
+ * possibly-invalid data; also remove segments of old data.
+ */
+ if (!track_commit_timestamp)
+ {
+ LWLockAcquire(CommitTsLock, LW_EXCLUSIVE);
+ ShmemVariableCache->oldestCommitTs = InvalidTransactionId;
+ ShmemVariableCache->newestCommitTs = InvalidTransactionId;
+ LWLockRelease(CommitTsLock);
+
+ TruncateCommitTs(ReadNewTransactionId());
+
+ return;
+ }
+
+ /*
+ * If CommitTs is enabled, but it wasn't in the previous server run, we
+ * need to set the oldest and newest values to the next Xid; that way, we
+ * will not try to read data that might not have been set.
+ *
+ * XXX does this have a problem if a server is started with commitTs
+ * enabled, then started with commitTs disabled, then restarted with it
+ * enabled again? It doesn't look like it does, because there should be a
+ * checkpoint that sets the value to InvalidTransactionId at end of
+ * recovery; and so any chance of injecting new transactions without
+ * CommitTs values would occur after the oldestCommitTs has been set to
+ * Invalid temporarily.
+ */
+ LWLockAcquire(CommitTsLock, LW_EXCLUSIVE);
+ if (ShmemVariableCache->oldestCommitTs == InvalidTransactionId)
+ {
+ ShmemVariableCache->oldestCommitTs =
+ ShmemVariableCache->newestCommitTs = ReadNewTransactionId();
+ }
+ LWLockRelease(CommitTsLock);
+
+ /* Finally, create the current segment file, if necessary */
+ if (!SimpleLruDoesPhysicalPageExist(CommitTsCtl, pageno))
+ {
+ int slotno;
+
+ LWLockAcquire(CommitTsControlLock, LW_EXCLUSIVE);
+ slotno = ZeroCommitTsPage(pageno, false);
+ SimpleLruWritePage(CommitTsCtl, slotno);
+ Assert(!CommitTsCtl->shared->page_dirty[slotno]);
+ LWLockRelease(CommitTsControlLock);
+ }
+}
+
+/*
+ * This must be called ONCE during postmaster or standalone-backend shutdown
+ */
+void
+ShutdownCommitTs(void)
+{
+ /* Flush dirty CommitTs pages to disk */
+ SimpleLruFlush(CommitTsCtl, false);
+}
+
+/*
+ * Perform a checkpoint --- either during shutdown, or on-the-fly
+ */
+void
+CheckPointCommitTs(void)
+{
+ /* Flush dirty CommitTs pages to disk */
+ SimpleLruFlush(CommitTsCtl, true);
+}
+
+/*
+ * Make sure that CommitTs has room for a newly-allocated XID.
+ *
+ * NB: this is called while holding XidGenLock. We want it to be very fast
+ * most of the time; even when it's not so fast, no actual I/O need happen
+ * unless we're forced to write out a dirty CommitTs or xlog page to make room
+ * in shared memory.
+ *
+ * NB: the current implementation relies on track_commit_timestamp being
+ * PGC_POSTMASTER.
+ */
+void
+ExtendCommitTs(TransactionId newestXact)
+{
+ int pageno;
+
+ /* nothing to do if module not enabled */
+ if (!track_commit_timestamp)
+ return;
+
+ /*
+ * No work except at first XID of a page. But beware: just after
+ * wraparound, the first XID of page zero is FirstNormalTransactionId.
+ */
+ if (TransactionIdToCTsEntry(newestXact) != 0 &&
+ !TransactionIdEquals(newestXact, FirstNormalTransactionId))
+ return;
+
+ pageno = TransactionIdToCTsPage(newestXact);
+
+ LWLockAcquire(CommitTsControlLock, LW_EXCLUSIVE);
+
+ /* Zero the page and make an XLOG entry about it */
+ ZeroCommitTsPage(pageno, !InRecovery);
+
+ LWLockRelease(CommitTsControlLock);
+}
+
+/*
+ * Remove all CommitTs segments before the one holding the passed
+ * transaction ID.
+ *
+ * Note that we don't need to flush XLOG here.
+ */
+void
+TruncateCommitTs(TransactionId oldestXact)
+{
+ int cutoffPage;
+
+ /*
+ * The cutoff point is the start of the segment containing oldestXact. We
+ * pass the *page* containing oldestXact to SimpleLruTruncate.
+ */
+ cutoffPage = TransactionIdToCTsPage(oldestXact);
+
+ /* Check to see if there's any files that could be removed */
+ if (!SlruScanDirectory(CommitTsCtl, SlruScanDirCbReportPresence,
+ &cutoffPage))
+ return; /* nothing to remove */
+
+ /* Write XLOG record */
+ WriteTruncateXlogRec(cutoffPage);
+
+ /* Now we can remove the old CommitTs segment(s) */
+ SimpleLruTruncate(CommitTsCtl, cutoffPage);
+}
+
+/*
+ * Set the limit values between which commit TS can be consulted.
+ */
+void
+SetCommitTsLimit(TransactionId oldestXact, TransactionId newestXact)
+{
+ /*
+ * Be careful not to overwrite values that are either further into the
+ * "future" or signal a disabled committs.
+ */
+ LWLockAcquire(CommitTsLock, LW_EXCLUSIVE);
+ if (ShmemVariableCache->oldestCommitTs != InvalidTransactionId)
+ {
+ if (TransactionIdPrecedes(ShmemVariableCache->oldestCommitTs, oldestXact))
+ ShmemVariableCache->oldestCommitTs = oldestXact;
+ if (TransactionIdPrecedes(newestXact, ShmemVariableCache->newestCommitTs))
+ ShmemVariableCache->newestCommitTs = newestXact;
+ }
+ else
+ {
+ Assert(ShmemVariableCache->newestCommitTs == InvalidTransactionId);
+ }
+ LWLockRelease(CommitTsLock);
+}
+
+/*
+ * Move forwards the oldest commitTS value that can be consulted
+ */
+void
+AdvanceOldestCommitTs(TransactionId oldestXact)
+{
+ LWLockAcquire(CommitTsLock, LW_EXCLUSIVE);
+ if (ShmemVariableCache->oldestCommitTs != InvalidTransactionId &&
+ TransactionIdPrecedes(ShmemVariableCache->oldestCommitTs, oldestXact))
+ ShmemVariableCache->oldestCommitTs = oldestXact;
+ LWLockRelease(CommitTsLock);
+}
+
+
+/*
+ * Decide which of two CLOG page numbers is "older" for truncation purposes.
+ *
+ * We need to use comparison of TransactionIds here in order to do the right
+ * thing with wraparound XID arithmetic. However, if we are asked about
+ * page number zero, we don't want to hand InvalidTransactionId to
+ * TransactionIdPrecedes: it'll get weird about permanent xact IDs. So,
+ * offset both xids by FirstNormalTransactionId to avoid that.
+ */
+static bool
+CommitTsPagePrecedes(int page1, int page2)
+{
+ TransactionId xid1;
+ TransactionId xid2;
+
+ xid1 = ((TransactionId) page1) * COMMIT_TS_XACTS_PER_PAGE;
+ xid1 += FirstNormalTransactionId;
+ xid2 = ((TransactionId) page2) * COMMIT_TS_XACTS_PER_PAGE;
+ xid2 += FirstNormalTransactionId;
+
+ return TransactionIdPrecedes(xid1, xid2);
+}
+
+
+/*
+ * Write a ZEROPAGE xlog record
+ */
+static void
+WriteZeroPageXlogRec(int pageno)
+{
+ XLogBeginInsert();
+ XLogRegisterData((char *) (&pageno), sizeof(int));
+ (void) XLogInsert(RM_COMMIT_TS_ID, COMMIT_TS_ZEROPAGE);
+}
+
+/*
+ * Write a TRUNCATE xlog record
+ */
+static void
+WriteTruncateXlogRec(int pageno)
+{
+ XLogBeginInsert();
+ XLogRegisterData((char *) (&pageno), sizeof(int));
+ (void) XLogInsert(RM_COMMIT_TS_ID, COMMIT_TS_TRUNCATE);
+}
+
+/*
+ * Write a SETTS xlog record
+ */
+static void
+WriteSetTimestampXlogRec(TransactionId mainxid, int nsubxids,
+ TransactionId *subxids, TimestampTz timestamp,
+ CommitTsNodeId nodeid)
+{
+ xl_commit_ts_set record;
+
+ record.timestamp = timestamp;
+ record.nodeid = nodeid;
+ record.mainxid = mainxid;
+
+ XLogBeginInsert();
+ XLogRegisterData((char *) &record,
+ offsetof(xl_commit_ts_set, mainxid) +
+ sizeof(TransactionId));
+ XLogRegisterData((char *) subxids, nsubxids * sizeof(TransactionId));
+ XLogInsert(RM_COMMIT_TS_ID, COMMIT_TS_SETTS);
+}
+
+/*
+ * CommitTS resource manager's routines
+ */
+void
+commit_ts_redo(XLogReaderState *record)
+{
+ uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
+
+ /* Backup blocks are not used in commit_ts records */
+ Assert(!XLogRecHasAnyBlockRefs(record));
+
+ if (info == COMMIT_TS_ZEROPAGE)
+ {
+ int pageno;
+ int slotno;
+
+ memcpy(&pageno, XLogRecGetData(record), sizeof(int));
+
+ LWLockAcquire(CommitTsControlLock, LW_EXCLUSIVE);
+
+ slotno = ZeroCommitTsPage(pageno, false);
+ SimpleLruWritePage(CommitTsCtl, slotno);
+ Assert(!CommitTsCtl->shared->page_dirty[slotno]);
+
+ LWLockRelease(CommitTsControlLock);
+ }
+ else if (info == COMMIT_TS_TRUNCATE)
+ {
+ int pageno;
+
+ memcpy(&pageno, XLogRecGetData(record), sizeof(int));
+
+ /*
+ * During XLOG replay, latest_page_number isn't set up yet; insert a
+ * suitable value to bypass the sanity test in SimpleLruTruncate.
+ */
+ CommitTsCtl->shared->latest_page_number = pageno;
+
+ SimpleLruTruncate(CommitTsCtl, pageno);
+ }
+ else if (info == COMMIT_TS_SETTS)
+ {
+ xl_commit_ts_set *setts = (xl_commit_ts_set *) XLogRecGetData(record);
+ int nsubxids;
+ TransactionId *subxids;
+
+ nsubxids = ((XLogRecGetDataLen(record) - SizeOfCommitTsSet) /
+ sizeof(TransactionId));
+ if (nsubxids > 0)
+ {
+ subxids = palloc(sizeof(TransactionId) * nsubxids);
+ memcpy(subxids,
+ XLogRecGetData(record) + SizeOfCommitTsSet,
+ sizeof(TransactionId) * nsubxids);
+ }
+ else
+ subxids = NULL;
+
+ TransactionTreeSetCommitTsData(setts->mainxid, nsubxids, subxids,
+ setts->timestamp, setts->nodeid, false);
+ if (subxids)
+ pfree(subxids);
+ }
+ else
+ elog(PANIC, "commit_ts_redo: unknown op code %u", info);
+}
#include "postgres.h"
#include "access/clog.h"
+#include "access/commit_ts.h"
#include "access/gin.h"
#include "access/gist_private.h"
#include "access/hash.h"
len = strlen(clde->d_name);
- if ((len == 4 || len == 5) &&
+ if ((len == 4 || len == 5 || len == 6) &&
strspn(clde->d_name, "0123456789ABCDEF") == len)
{
segno = (int) strtol(clde->d_name, NULL, 16);
#include "postgres.h"
#include "access/clog.h"
+#include "access/commit_ts.h"
#include "access/subtrans.h"
#include "access/transam.h"
#include "access/xact.h"
* XID before we zero the page. Fortunately, a page of the commit log
* holds 32K or more transactions, so we don't have to do this very often.
*
- * Extend pg_subtrans too.
+ * Extend pg_subtrans and pg_commit_ts too.
*/
ExtendCLOG(xid);
+ ExtendCommitTs(xid);
ExtendSUBTRANS(xid);
/*
#include <time.h>
#include <unistd.h>
+#include "access/commit_ts.h"
#include "access/multixact.h"
#include "access/subtrans.h"
#include "access/transam.h"
}
}
+ /*
+ * We only need to log the commit timestamp separately if the node
+ * identifier is a valid value; the commit record above already contains
+ * the timestamp info otherwise, and will be used to load it.
+ */
+ if (markXidCommitted)
+ {
+ CommitTsNodeId node_id;
+
+ node_id = CommitTsGetDefaultNodeId();
+ TransactionTreeSetCommitTsData(xid, nchildren, children,
+ xactStopTimestamp,
+ node_id, node_id != InvalidCommitTsNodeId);
+ }
+
/*
* Check if we want to commit asynchronously. We can allow the XLOG flush
* to happen asynchronously if synchronous_commit=off, or if the current
*/
static void
xact_redo_commit_internal(TransactionId xid, XLogRecPtr lsn,
+ TimestampTz commit_time,
TransactionId *sub_xids, int nsubxacts,
SharedInvalidationMessage *inval_msgs, int nmsgs,
RelFileNode *xnodes, int nrels,
LWLockRelease(XidGenLock);
}
+ /* Set the transaction commit timestamp and metadata */
+ TransactionTreeSetCommitTsData(xid, nsubxacts, sub_xids,
+ commit_time, InvalidCommitTsNodeId, false);
+
if (standbyState == STANDBY_DISABLED)
{
/*
/* invalidation messages array follows subxids */
inval_msgs = (SharedInvalidationMessage *) &(subxacts[xlrec->nsubxacts]);
- xact_redo_commit_internal(xid, lsn, subxacts, xlrec->nsubxacts,
+ xact_redo_commit_internal(xid, lsn, xlrec->xact_time,
+ subxacts, xlrec->nsubxacts,
inval_msgs, xlrec->nmsgs,
xlrec->xnodes, xlrec->nrels,
xlrec->dbId,
xact_redo_commit_compact(xl_xact_commit_compact *xlrec,
TransactionId xid, XLogRecPtr lsn)
{
- xact_redo_commit_internal(xid, lsn, xlrec->subxacts, xlrec->nsubxacts,
+ xact_redo_commit_internal(xid, lsn, xlrec->xact_time,
+ xlrec->subxacts, xlrec->nsubxacts,
NULL, 0, /* inval msgs */
NULL, 0, /* relfilenodes */
InvalidOid, /* dbId */
#include <unistd.h>
#include "access/clog.h"
+#include "access/commit_ts.h"
#include "access/multixact.h"
#include "access/rewriteheap.h"
#include "access/subtrans.h"
checkPoint.oldestXidDB = TemplateDbOid;
checkPoint.oldestMulti = FirstMultiXactId;
checkPoint.oldestMultiDB = TemplateDbOid;
+ checkPoint.oldestCommitTs = InvalidTransactionId;
+ checkPoint.newestCommitTs = InvalidTransactionId;
checkPoint.time = (pg_time_t) time(NULL);
checkPoint.oldestActiveXid = InvalidTransactionId;
MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
SetMultiXactIdLimit(checkPoint.oldestMulti, checkPoint.oldestMultiDB);
+ SetCommitTsLimit(InvalidTransactionId, InvalidTransactionId);
/* Set up the XLOG page header */
page->xlp_magic = XLOG_PAGE_MAGIC;
ControlFile->max_locks_per_xact = max_locks_per_xact;
ControlFile->wal_level = wal_level;
ControlFile->wal_log_hints = wal_log_hints;
+ ControlFile->track_commit_timestamp = track_commit_timestamp;
ControlFile->data_checksum_version = bootstrap_data_checksum_version;
/* some additional ControlFile fields are set in WriteControlFile() */
/* Bootstrap the commit log, too */
BootStrapCLOG();
+ BootStrapCommitTs();
BootStrapSUBTRANS();
BootStrapMultiXact();
ereport(DEBUG1,
(errmsg("oldest MultiXactId: %u, in database %u",
checkPoint.oldestMulti, checkPoint.oldestMultiDB)));
+ ereport(DEBUG1,
+ (errmsg("commit timestamp Xid oldest/newest: %u/%u",
+ checkPoint.oldestCommitTs,
+ checkPoint.newestCommitTs)));
if (!TransactionIdIsNormal(checkPoint.nextXid))
ereport(PANIC,
(errmsg("invalid next transaction ID")));
MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
SetMultiXactIdLimit(checkPoint.oldestMulti, checkPoint.oldestMultiDB);
+ SetCommitTsLimit(checkPoint.oldestCommitTs,
+ checkPoint.newestCommitTs);
MultiXactSetSafeTruncate(checkPoint.oldestMulti);
XLogCtl->ckptXidEpoch = checkPoint.nextXidEpoch;
XLogCtl->ckptXid = checkPoint.nextXid;
ProcArrayInitRecovery(ShmemVariableCache->nextXid);
/*
- * Startup commit log and subtrans only. MultiXact has already
- * been started up and other SLRUs are not maintained during
- * recovery and need not be started yet.
+ * Startup commit log, commit timestamp and subtrans only.
+ * MultiXact has already been started up and other SLRUs are not
+ * maintained during recovery and need not be started yet.
*/
StartupCLOG();
+ StartupCommitTs();
StartupSUBTRANS(oldestActiveXID);
/*
LWLockRelease(ProcArrayLock);
/*
- * Start up the commit log and subtrans, if not already done for hot
- * standby.
+ * Start up the commit log, commit timestamp and subtrans, if not already
+ * done for hot standby.
*/
if (standbyState == STANDBY_DISABLED)
{
StartupCLOG();
+ StartupCommitTs();
StartupSUBTRANS(oldestActiveXID);
}
LocalSetXLogInsertAllowed();
XLogReportParameters();
+ /*
+ * Local WAL inserts enabled, so it's time to finish initialization
+ * of commit timestamp.
+ */
+ CompleteCommitTsInitialization();
+
/*
* All done. Allow backends to write WAL. (Although the bool flag is
* probably atomic in itself, we use the info_lck here to ensure that
CreateCheckPoint(CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_IMMEDIATE);
}
ShutdownCLOG();
+ ShutdownCommitTs();
ShutdownSUBTRANS();
ShutdownMultiXact();
checkPoint.oldestXidDB = ShmemVariableCache->oldestXidDB;
LWLockRelease(XidGenLock);
+ LWLockAcquire(CommitTsLock, LW_SHARED);
+ checkPoint.oldestCommitTs = ShmemVariableCache->oldestCommitTs;
+ checkPoint.newestCommitTs = ShmemVariableCache->newestCommitTs;
+ LWLockRelease(CommitTsLock);
+
/* Increase XID epoch if we've wrapped around since last checkpoint */
checkPoint.nextXidEpoch = ControlFile->checkPointCopy.nextXidEpoch;
if (checkPoint.nextXid < ControlFile->checkPointCopy.nextXid)
CheckPointGuts(XLogRecPtr checkPointRedo, int flags)
{
CheckPointCLOG();
+ CheckPointCommitTs();
CheckPointSUBTRANS();
CheckPointMultiXact();
CheckPointPredicate();
MaxConnections != ControlFile->MaxConnections ||
max_worker_processes != ControlFile->max_worker_processes ||
max_prepared_xacts != ControlFile->max_prepared_xacts ||
- max_locks_per_xact != ControlFile->max_locks_per_xact)
+ max_locks_per_xact != ControlFile->max_locks_per_xact ||
+ track_commit_timestamp != ControlFile->track_commit_timestamp)
{
/*
* The change in number of backend slots doesn't need to be WAL-logged
xlrec.max_locks_per_xact = max_locks_per_xact;
xlrec.wal_level = wal_level;
xlrec.wal_log_hints = wal_log_hints;
+ xlrec.track_commit_timestamp = track_commit_timestamp;
XLogBeginInsert();
XLogRegisterData((char *) &xlrec, sizeof(xlrec));
ControlFile->max_locks_per_xact = max_locks_per_xact;
ControlFile->wal_level = wal_level;
ControlFile->wal_log_hints = wal_log_hints;
+ ControlFile->track_commit_timestamp = track_commit_timestamp;
UpdateControlFile();
}
}
ControlFile->max_locks_per_xact = xlrec.max_locks_per_xact;
ControlFile->wal_level = xlrec.wal_level;
ControlFile->wal_log_hints = wal_log_hints;
+ ControlFile->track_commit_timestamp = track_commit_timestamp;
/*
* Update minRecoveryPoint to ensure that if recovery is aborted, we
#include <math.h>
#include "access/clog.h"
+#include "access/commit_ts.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "access/htup_details.h"
return;
/*
- * Truncate CLOG to the oldest computed value. Note we don't truncate
- * multixacts; that will be done by the next checkpoint.
+ * Truncate CLOG and CommitTs to the oldest computed value.
+ * Note we don't truncate multixacts; that will be done by the next
+ * checkpoint.
*/
TruncateCLOG(frozenXID);
+ TruncateCommitTs(frozenXID);
/*
* Update the wrap limit for GetNewTransactionId and creation of new
*/
SetTransactionIdLimit(frozenXID, oldestxid_datoid);
SetMultiXactIdLimit(minMulti, minmulti_datoid);
+ AdvanceOldestCommitTs(frozenXID);
}
ereport(LOG,
(errcode(ERRCODE_CONFIG_FILE_ERROR),
errmsg("client certificates can only be checked if a root certificate store is available"),
- errhint("Make sure the configuration parameter \"ssl_ca_file\" is set."),
+ errhint("Make sure the configuration parameter \"%s\" is set.", "ssl_ca_file"),
errcontext("line %d of configuration file \"%s\"",
line_num, HbaFileName)));
return false;
case RM_SEQ_ID:
case RM_SPGIST_ID:
case RM_BRIN_ID:
+ case RM_COMMIT_TS_ID:
break;
case RM_NEXT_ID:
elog(ERROR, "unexpected RM_NEXT_ID rmgr_id: %u", (RmgrIds) XLogRecGetRmid(buf.record));
#include "postgres.h"
#include "access/clog.h"
+#include "access/commit_ts.h"
#include "access/heapam.h"
#include "access/multixact.h"
#include "access/nbtree.h"
size = add_size(size, ProcGlobalShmemSize());
size = add_size(size, XLOGShmemSize());
size = add_size(size, CLOGShmemSize());
+ size = add_size(size, CommitTsShmemSize());
size = add_size(size, SUBTRANSShmemSize());
size = add_size(size, TwoPhaseShmemSize());
size = add_size(size, BackgroundWorkerShmemSize());
*/
XLOGShmemInit();
CLOGShmemInit();
+ CommitTsShmemInit();
SUBTRANSShmemInit();
MultiXactShmemInit();
InitBufferPool();
#include "postgres.h"
#include "access/clog.h"
+#include "access/commit_ts.h"
#include "access/multixact.h"
#include "access/subtrans.h"
#include "commands/async.h"
/* clog.c needs one per CLOG buffer */
numLocks += CLOGShmemBuffers();
+ /* commit_ts.c needs one per CommitTs buffer */
+ numLocks += CommitTsShmemBuffers();
+
/* subtrans.c needs one per SubTrans buffer */
numLocks += NUM_SUBTRANS_BUFFERS;
#include <syslog.h>
#endif
+#include "access/commit_ts.h"
#include "access/gin.h"
#include "access/transam.h"
#include "access/twophase.h"
false,
check_bonjour, NULL, NULL
},
+ {
+ {"track_commit_timestamp", PGC_POSTMASTER, REPLICATION,
+ gettext_noop("Collects transaction commit time."),
+ NULL
+ },
+ &track_commit_timestamp,
+ false,
+ NULL, NULL, NULL
+ },
{
{"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
gettext_noop("Enables SSL connections."),
#max_replication_slots = 0 # max number of replication slots
# (change requires restart)
+#track_commit_timestamp = off # collect timestamp of transaction commit
+ # (change requires restart)
# - Master Server -
"pg_xlog",
"pg_xlog/archive_status",
"pg_clog",
+ "pg_commit_ts",
"pg_dynshmem",
"pg_notify",
"pg_serial",
ControlFile.checkPointCopy.oldestMulti);
printf(_("Latest checkpoint's oldestMulti's DB: %u\n"),
ControlFile.checkPointCopy.oldestMultiDB);
+ printf(_("Latest checkpoint's oldestCommitTs: %u\n"),
+ ControlFile.checkPointCopy.oldestCommitTs);
printf(_("Time of latest checkpoint: %s\n"),
ckpttime_str);
printf(_("Fake LSN counter for unlogged rels: %X/%X\n"),
ControlFile.max_prepared_xacts);
printf(_("Current max_locks_per_xact setting: %d\n"),
ControlFile.max_locks_per_xact);
+ printf(_("Current track_commit_timestamp setting: %s\n"),
+ ControlFile.track_commit_timestamp ? _("on") : _("off"));
printf(_("Maximum data alignment: %u\n"),
ControlFile.maxAlign);
/* we don't print floatFormat since can't say much useful about it */
static const char *progname;
static uint32 set_xid_epoch = (uint32) -1;
static TransactionId set_xid = 0;
+static TransactionId set_oldest_commit_ts = 0;
+static TransactionId set_newest_commit_ts = 0;
static Oid set_oid = 0;
static MultiXactId set_mxid = 0;
static MultiXactOffset set_mxoff = (MultiXactOffset) -1;
}
- while ((c = getopt(argc, argv, "D:fl:m:no:O:x:e:")) != -1)
+ while ((c = getopt(argc, argv, "c:D:e:fl:m:no:O:x:")) != -1)
{
switch (c)
{
set_xid_epoch = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != '\0')
{
- fprintf(stderr, _("%s: invalid argument for option -e\n"), progname);
+ /*------
+ translator: the second %s is a command line argument (-e, etc) */
+ fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-e");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
set_xid = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != '\0')
{
- fprintf(stderr, _("%s: invalid argument for option -x\n"), progname);
+ fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-x");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
}
break;
+ case 'c':
+ set_oldest_commit_ts = strtoul(optarg, &endptr, 0);
+ if (endptr == optarg || *endptr != ',')
+ {
+ fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-c");
+ fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
+ exit(1);
+ }
+ set_newest_commit_ts = strtoul(endptr + 1, &endptr2, 0);
+ if (endptr2 == endptr + 1 || *endptr2 != '\0')
+ {
+ fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-c");
+ fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
+ exit(1);
+ }
+
+ if (set_oldest_commit_ts < 2 &&
+ set_oldest_commit_ts != 0)
+ {
+ fprintf(stderr, _("%s: transaction ID (-c) must be either 0 or greater than or equal to 2\n"), progname);
+ exit(1);
+ }
+
+ if (set_newest_commit_ts < 2 &&
+ set_newest_commit_ts != 0)
+ {
+ fprintf(stderr, _("%s: transaction ID (-c) must be either 0 or greater than or equal to 2\n"), progname);
+ exit(1);
+ }
+ break;
+
case 'o':
set_oid = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != '\0')
{
- fprintf(stderr, _("%s: invalid argument for option -o\n"), progname);
+ fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-o");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
set_mxid = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != ',')
{
- fprintf(stderr, _("%s: invalid argument for option -m\n"), progname);
+ fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-m");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
set_oldestmxid = strtoul(endptr + 1, &endptr2, 0);
if (endptr2 == endptr + 1 || *endptr2 != '\0')
{
- fprintf(stderr, _("%s: invalid argument for option -m\n"), progname);
+ fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-m");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
set_mxoff = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != '\0')
{
- fprintf(stderr, _("%s: invalid argument for option -O\n"), progname);
+ fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-O");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
case 'l':
if (strspn(optarg, "01234567890ABCDEFabcdef") != 24)
{
- fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
+ fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-l");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
}
+ if (set_oldest_commit_ts != 0)
+ ControlFile.checkPointCopy.oldestCommitTs = set_oldest_commit_ts;
+ if (set_newest_commit_ts != 0)
+ ControlFile.checkPointCopy.newestCommitTs = set_newest_commit_ts;
+
if (set_oid != 0)
ControlFile.checkPointCopy.nextOid = set_oid;
ControlFile.wal_level = WAL_LEVEL_MINIMAL;
ControlFile.wal_log_hints = false;
+ ControlFile.track_commit_timestamp = false;
ControlFile.MaxConnections = 100;
ControlFile.max_worker_processes = 8;
ControlFile.max_prepared_xacts = 0;
ControlFile.checkPointCopy.oldestMulti);
printf(_("Latest checkpoint's oldestMulti's DB: %u\n"),
ControlFile.checkPointCopy.oldestMultiDB);
+ printf(_("Latest checkpoint's oldest CommitTs: %u\n"),
+ ControlFile.checkPointCopy.oldestCommitTs);
+ printf(_("Latest checkpoint's newest CommitTs: %u\n"),
+ ControlFile.checkPointCopy.newestCommitTs);
printf(_("Maximum data alignment: %u\n"),
ControlFile.maxAlign);
/* we don't print floatFormat since can't say much useful about it */
printf(_("NextXID epoch: %u\n"),
ControlFile.checkPointCopy.nextXidEpoch);
}
+
+ if (set_oldest_commit_ts != 0)
+ {
+ printf(_("oldestCommitTs: %u\n"),
+ ControlFile.checkPointCopy.oldestCommitTs);
+ }
+ if (set_newest_commit_ts != 0)
+ {
+ printf(_("newestCommitTs: %u\n"),
+ ControlFile.checkPointCopy.newestCommitTs);
+ }
}
*/
ControlFile.wal_level = WAL_LEVEL_MINIMAL;
ControlFile.wal_log_hints = false;
+ ControlFile.track_commit_timestamp = false;
ControlFile.MaxConnections = 100;
ControlFile.max_worker_processes = 8;
ControlFile.max_prepared_xacts = 0;
printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
printf(_("Usage:\n %s [OPTION]... {[-D] DATADIR}\n\n"), progname);
printf(_("Options:\n"));
+ printf(_(" -c XID,XID set oldest and newest transactions bearing commit timestamp\n"));
+ printf(_(" (zero in either value means no change)\n"));
printf(_(" -e XIDEPOCH set next transaction ID epoch\n"));
printf(_(" -f force update to be done\n"));
printf(_(" -l XLOGFILE force minimum WAL starting location for new transaction log\n"));
--- /dev/null
+/*
+ * commit_ts.h
+ *
+ * PostgreSQL commit timestamp manager
+ *
+ * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/access/commit_ts.h
+ */
+#ifndef COMMIT_TS_H
+#define COMMIT_TS_H
+
+#include "access/xlog.h"
+#include "datatype/timestamp.h"
+#include "utils/guc.h"
+
+
+extern PGDLLIMPORT bool track_commit_timestamp;
+
+extern bool check_track_commit_timestamp(bool *newval, void **extra,
+ GucSource source);
+
+typedef uint32 CommitTsNodeId;
+#define InvalidCommitTsNodeId 0
+
+extern void CommitTsSetDefaultNodeId(CommitTsNodeId nodeid);
+extern CommitTsNodeId CommitTsGetDefaultNodeId(void);
+extern void TransactionTreeSetCommitTsData(TransactionId xid, int nsubxids,
+ TransactionId *subxids, TimestampTz timestamp,
+ CommitTsNodeId nodeid, bool do_xlog);
+extern bool TransactionIdGetCommitTsData(TransactionId xid,
+ TimestampTz *ts, CommitTsNodeId *nodeid);
+extern TransactionId GetLatestCommitTsData(TimestampTz *ts,
+ CommitTsNodeId *nodeid);
+
+extern Size CommitTsShmemBuffers(void);
+extern Size CommitTsShmemSize(void);
+extern void CommitTsShmemInit(void);
+extern void BootStrapCommitTs(void);
+extern void StartupCommitTs(void);
+extern void CompleteCommitTsInitialization(void);
+extern void ShutdownCommitTs(void);
+extern void CheckPointCommitTs(void);
+extern void ExtendCommitTs(TransactionId newestXact);
+extern void TruncateCommitTs(TransactionId oldestXact);
+extern void SetCommitTsLimit(TransactionId oldestXact,
+ TransactionId newestXact);
+extern void AdvanceOldestCommitTs(TransactionId oldestXact);
+
+/* XLOG stuff */
+#define COMMIT_TS_ZEROPAGE 0x00
+#define COMMIT_TS_TRUNCATE 0x10
+#define COMMIT_TS_SETTS 0x20
+
+typedef struct xl_commit_ts_set
+{
+ TimestampTz timestamp;
+ CommitTsNodeId nodeid;
+ TransactionId mainxid;
+ /* subxact Xids follow */
+} xl_commit_ts_set;
+
+#define SizeOfCommitTsSet (offsetof(xl_commit_ts_set, mainxid) + \
+ sizeof(TransactionId))
+
+
+extern void commit_ts_redo(XLogReaderState *record);
+extern void commit_ts_desc(StringInfo buf, XLogReaderState *record);
+extern const char *commit_ts_identify(uint8 info);
+
+#endif /* COMMITTS_H */
PG_RMGR(RM_SEQ_ID, "Sequence", seq_redo, seq_desc, seq_identify, NULL, NULL)
PG_RMGR(RM_SPGIST_ID, "SPGist", spg_redo, spg_desc, spg_identify, spg_xlog_startup, spg_xlog_cleanup)
PG_RMGR(RM_BRIN_ID, "BRIN", brin_redo, brin_desc, brin_identify, NULL, NULL)
+PG_RMGR(RM_COMMIT_TS_ID, "CommitTs", commit_ts_redo, commit_ts_desc, commit_ts_identify, NULL, NULL)
TransactionId xidWrapLimit; /* where the world ends */
Oid oldestXidDB; /* database with minimum datfrozenxid */
+ /*
+ * These fields are protected by CommitTsLock
+ */
+ TransactionId oldestCommitTs;
+ TransactionId newestCommitTs;
+
/*
* These fields are protected by ProcArrayLock.
*/
int max_locks_per_xact;
int wal_level;
bool wal_log_hints;
+ bool track_commit_timestamp;
} xl_parameter_change;
/* logs restore point */
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 201412021
+#define CATALOG_VERSION_NO 201412022
#endif
MultiXactId oldestMulti; /* cluster-wide minimum datminmxid */
Oid oldestMultiDB; /* database with minimum datminmxid */
pg_time_t time; /* time stamp of checkpoint */
+ TransactionId oldestCommitTs; /* oldest Xid with valid commit timestamp */
+ TransactionId newestCommitTs; /* newest Xid with valid commit timestamp */
/*
* Oldest XID still running. This is only needed to initialize hot standby
int max_worker_processes;
int max_prepared_xacts;
int max_locks_per_xact;
+ bool track_commit_timestamp;
/*
* This data is used to check for hardware-architecture compatibility of
DATA(insert OID = 3819 ( pg_get_multixact_members PGNSP PGUID 12 1 1000 0 0 f f f f t t v 1 0 2249 "28" "{28,28,25}" "{i,o,o}" "{multixid,xid,mode}" _null_ pg_get_multixact_members _null_ _null_ _null_ ));
DESCR("view members of a multixactid");
+DATA(insert OID = 3581 ( pg_xact_commit_timestamp PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 1184 "28" _null_ _null_ _null_ _null_ pg_xact_commit_timestamp _null_ _null_ _null_ ));
+DESCR("get commit timestamp of a transaction");
+
+DATA(insert OID = 3583 ( pg_last_committed_xact PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 2249 "" "{28,1184}" "{o,o}" "{xid,timestamp}" _null_ pg_last_committed_xact _null_ _null_ _null_ ));
+DESCR("get transaction Id and commit timestamp of latest transaction commit");
+
DATA(insert OID = 3537 ( pg_describe_object PGNSP PGUID 12 1 0 0 0 f f f f t f s 3 0 25 "26 26 23" _null_ _null_ _null_ _null_ pg_describe_object _null_ _null_ _null_ ));
DESCR("get identification of SQL object");
#define AutoFileLock (&MainLWLockArray[35].lock)
#define ReplicationSlotAllocationLock (&MainLWLockArray[36].lock)
#define ReplicationSlotControlLock (&MainLWLockArray[37].lock)
-#define NUM_INDIVIDUAL_LWLOCKS 38
+#define CommitTsControlLock (&MainLWLockArray[38].lock)
+#define CommitTsLock (&MainLWLockArray[39].lock)
+
+#define NUM_INDIVIDUAL_LWLOCKS 40
/*
* It's a bit odd to declare NUM_BUFFER_PARTITIONS and NUM_LOCK_PARTITIONS
/* access/transam/multixact.c */
extern Datum pg_get_multixact_members(PG_FUNCTION_ARGS);
+/* access/transam/committs.c */
+extern Datum pg_xact_commit_timestamp(PG_FUNCTION_ARGS);
+extern Datum pg_last_committed_xact(PG_FUNCTION_ARGS);
+
/* catalogs/dependency.c */
extern Datum pg_describe_object(PG_FUNCTION_ARGS);
extern Datum pg_identify_object(PG_FUNCTION_ARGS);
include $(top_builddir)/src/Makefile.global
SUBDIRS = \
+ commit_ts \
worker_spi \
dummy_seclabel \
test_shm_mq \
--- /dev/null
+# Generated subdirectories
+/log/
+/results/
+/tmp_check/
--- /dev/null
+# src/test/modules/commit_ts/Makefile
+
+REGRESS = commit_timestamp
+REGRESS_OPTS = --temp-config=$(top_srcdir)/src/test/modules/commit_ts/commit_ts.conf
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/commit_ts
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
--- /dev/null
+track_commit_timestamp = on
\ No newline at end of file
--- /dev/null
+--
+-- Commit Timestamp
+--
+SHOW track_commit_timestamp;
+ track_commit_timestamp
+------------------------
+ on
+(1 row)
+
+CREATE TABLE committs_test(id serial, ts timestamptz default now());
+INSERT INTO committs_test DEFAULT VALUES;
+INSERT INTO committs_test DEFAULT VALUES;
+INSERT INTO committs_test DEFAULT VALUES;
+SELECT id,
+ pg_xact_commit_timestamp(xmin) >= ts,
+ pg_xact_commit_timestamp(xmin) < now(),
+ pg_xact_commit_timestamp(xmin) - ts < '60s' -- 60s should give a lot of reserve
+FROM committs_test
+ORDER BY id;
+ id | ?column? | ?column? | ?column?
+----+----------+----------+----------
+ 1 | t | t | t
+ 2 | t | t | t
+ 3 | t | t | t
+(3 rows)
+
+DROP TABLE committs_test;
+SELECT pg_xact_commit_timestamp('0'::xid);
+ERROR: cannot retrieve commit timestamp for transaction 0
+SELECT pg_xact_commit_timestamp('1'::xid);
+ERROR: cannot retrieve commit timestamp for transaction 1
+SELECT pg_xact_commit_timestamp('2'::xid);
+ERROR: cannot retrieve commit timestamp for transaction 2
+SELECT x.xid::text::bigint > 0, x.timestamp > '-infinity'::timestamptz, x.timestamp < now() FROM pg_last_committed_xact() x;
+ ?column? | ?column? | ?column?
+----------+----------+----------
+ t | t | t
+(1 row)
+
--- /dev/null
+--
+-- Commit Timestamp
+--
+SHOW track_commit_timestamp;
+ track_commit_timestamp
+------------------------
+ off
+(1 row)
+
+CREATE TABLE committs_test(id serial, ts timestamptz default now());
+INSERT INTO committs_test DEFAULT VALUES;
+INSERT INTO committs_test DEFAULT VALUES;
+INSERT INTO committs_test DEFAULT VALUES;
+SELECT id,
+ pg_xact_commit_timestamp(xmin) >= ts,
+ pg_xact_commit_timestamp(xmin) < now(),
+ pg_xact_commit_timestamp(xmin) - ts < '60s' -- 60s should give a lot of reserve
+FROM committs_test
+ORDER BY id;
+ERROR: could not get commit timestamp data
+HINT: Make sure the configuration parameter "track_commit_timestamp" is set.
+DROP TABLE committs_test;
+SELECT pg_xact_commit_timestamp('0'::xid);
+ERROR: could not get commit timestamp data
+HINT: Make sure the configuration parameter "track_commit_timestamp" is set.
+SELECT pg_xact_commit_timestamp('1'::xid);
+ERROR: could not get commit timestamp data
+HINT: Make sure the configuration parameter "track_commit_timestamp" is set.
+SELECT pg_xact_commit_timestamp('2'::xid);
+ERROR: could not get commit timestamp data
+HINT: Make sure the configuration parameter "track_commit_timestamp" is set.
+SELECT x.xid::text::bigint > 0, x.timestamp > '-infinity'::timestamptz, x.timestamp < now() FROM pg_last_committed_xact() x;
+ERROR: could not get commit timestamp data
+HINT: Make sure the configuration parameter "track_commit_timestamp" is set.
--- /dev/null
+--
+-- Commit Timestamp
+--
+SHOW track_commit_timestamp;
+CREATE TABLE committs_test(id serial, ts timestamptz default now());
+
+INSERT INTO committs_test DEFAULT VALUES;
+INSERT INTO committs_test DEFAULT VALUES;
+INSERT INTO committs_test DEFAULT VALUES;
+
+SELECT id,
+ pg_xact_commit_timestamp(xmin) >= ts,
+ pg_xact_commit_timestamp(xmin) < now(),
+ pg_xact_commit_timestamp(xmin) - ts < '60s' -- 60s should give a lot of reserve
+FROM committs_test
+ORDER BY id;
+
+DROP TABLE committs_test;
+
+SELECT pg_xact_commit_timestamp('0'::xid);
+SELECT pg_xact_commit_timestamp('1'::xid);
+SELECT pg_xact_commit_timestamp('2'::xid);
+
+SELECT x.xid::text::bigint > 0, x.timestamp > '-infinity'::timestamptz, x.timestamp < now() FROM pg_last_committed_xact() x;
projects / postgresql / commitdiff