diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
new file mode 100644
index 77a9303..1200ad6
*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
*************** include 'filename'
*** 1156,1163 ****
Note that when autovacuum runs, up to
! times this memory may be
! allocated, so be careful not to set the default value too high.
--- 1156,1181 ----
Note that when autovacuum runs, up to
! times this memory
! may be allocated, so be careful not to set the default value
! too high. It may be useful to control for this by separately
! setting .
!
!
!
!
!
! autovacuum_work_mem (integer)
!
! autovacuum_work_mem configuration parameter
!
!
!
! Specifies the maximum amount of memory to be used by each
! autovacuum worker process. It defaults to -1, indicating that
! the value of should
! be used instead. The setting has no effect on the behavior of
! VACUUM when run in other contexts.
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
new file mode 100644
index e1d6d1c..62bd2f0
*** a/src/backend/commands/vacuumlazy.c
--- b/src/backend/commands/vacuumlazy.c
***************
*** 10,22 ****
* relations with finite memory space usage. To do that, we set upper bounds
* on the number of tuples and pages we will keep track of at once.
*
! * We are willing to use at most maintenance_work_mem memory space to keep
! * track of dead tuples. We initially allocate an array of TIDs of that size,
! * with an upper limit that depends on table size (this limit ensures we don't
! * allocate a huge area uselessly for vacuuming small tables). If the array
! * threatens to overflow, we suspend the heap scan phase and perform a pass of
! * index cleanup and page compaction, then resume the heap scan with an empty
! * TID array.
*
* If we're processing a table with no indexes, we can just vacuum each page
* as we go; there's no need to save up multiple tuples to minimize the number
--- 10,22 ----
* relations with finite memory space usage. To do that, we set upper bounds
* on the number of tuples and pages we will keep track of at once.
*
! * We are willing to use at most maintenance_work_mem (or perhaps
! * autovacuum_work_mem) memory space to keep track of dead tuples. We
! * initially allocate an array of TIDs of that size, with an upper limit that
! * depends on table size (this limit ensures we don't allocate a huge area
! * uselessly for vacuuming small tables). If the array threatens to overflow,
! * we suspend the heap scan phase and perform a pass of index cleanup and page
! * compaction, then resume the heap scan with an empty TID array.
*
* If we're processing a table with no indexes, we can just vacuum each page
* as we go; there's no need to save up multiple tuples to minimize the number
*************** static void
*** 1581,1590 ****
lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks)
{
long maxtuples;
if (vacrelstats->hasindex)
{
! maxtuples = (maintenance_work_mem * 1024L) / sizeof(ItemPointerData);
maxtuples = Min(maxtuples, INT_MAX);
maxtuples = Min(maxtuples, MaxAllocSize / sizeof(ItemPointerData));
--- 1581,1593 ----
lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks)
{
long maxtuples;
+ int vac_work_mem = IsAutoVacuumWorkerProcess() &&
+ autovacuum_work_mem != -1 ?
+ autovacuum_work_mem : maintenance_work_mem;
if (vacrelstats->hasindex)
{
! maxtuples = (vac_work_mem * 1024L) / sizeof(ItemPointerData);
maxtuples = Min(maxtuples, INT_MAX);
maxtuples = Min(maxtuples, MaxAllocSize / sizeof(ItemPointerData));
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
new file mode 100644
index 8c14d0f..0b881c0
*** a/src/backend/postmaster/autovacuum.c
--- b/src/backend/postmaster/autovacuum.c
***************
*** 110,115 ****
--- 110,116 ----
*/
bool autovacuum_start_daemon = false;
int autovacuum_max_workers;
+ int autovacuum_work_mem = -1;
int autovacuum_naptime;
int autovacuum_vac_thresh;
double autovacuum_vac_scale;
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
new file mode 100644
index 54d8078..d33048f
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
*************** static const char *show_tcp_keepalives_c
*** 192,197 ****
--- 192,198 ----
static bool check_maxconnections(int *newval, void **extra, GucSource source);
static bool check_max_worker_processes(int *newval, void **extra, GucSource source);
static bool check_autovacuum_max_workers(int *newval, void **extra, GucSource source);
+ static bool check_autovacuum_work_mem(int *newval, void **extra, GucSource source);
static bool check_effective_io_concurrency(int *newval, void **extra, GucSource source);
static void assign_effective_io_concurrency(int newval, void *extra);
static void assign_pgstat_temp_directory(const char *newval, void *extra);
*************** static struct config_int ConfigureNamesI
*** 2347,2352 ****
--- 2348,2364 ----
},
{
+ {"autovacuum_work_mem", PGC_SIGHUP, RESOURCES_MEM,
+ gettext_noop("Sets the maximum memory to be used by each autovacuum worker process."),
+ NULL,
+ GUC_UNIT_KB
+ },
+ &autovacuum_work_mem,
+ -1, -1, MAX_KILOBYTES,
+ check_autovacuum_work_mem, NULL, NULL
+ },
+
+ {
{"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
gettext_noop("Time between issuing TCP keepalives."),
gettext_noop("A value of 0 uses the system default."),
*************** check_autovacuum_max_workers(int *newval
*** 8751,8756 ****
--- 8763,8791 ----
return true;
}
+ static bool
+ check_autovacuum_work_mem(int *newval, void **extra, GucSource source)
+ {
+ /*
+ * -1 indicates fallback.
+ *
+ * If we haven't yet changed the boot_val default of -1, just let it be.
+ * Autovacuum will look to maintenance_work_mem instead.
+ */
+ if (*newval == -1)
+ return true;
+
+ /*
+ * We clamp manually-set values to at least 1MB. Since
+ * maintenance_work_mem is always set to at least this value, do the same
+ * here.
+ */
+ if (*newval < 1024)
+ *newval = 1024;
+
+ return true;
+ }
+
static bool
check_max_worker_processes(int *newval, void **extra, GucSource source)
{
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
new file mode 100644
index 34a2d05..4737ede
*** a/src/backend/utils/misc/postgresql.conf.sample
--- b/src/backend/utils/misc/postgresql.conf.sample
***************
*** 122,127 ****
--- 122,128 ----
# actively intend to use prepared transactions.
#work_mem = 1MB # min 64kB
#maintenance_work_mem = 16MB # min 1MB
+ #autovacuum_work_mem = -1 # min 1MB, or -1 to use maintenance_work_mem
#max_stack_depth = 2MB # min 100kB
#dynamic_shared_memory_type = posix # the default is the first option
# supported by the operating system:
diff --git a/src/include/postmaster/autovacuum.h b/src/include/postmaster/autovacuum.h
new file mode 100644
index e96f07a..92560fe
*** a/src/include/postmaster/autovacuum.h
--- b/src/include/postmaster/autovacuum.h
***************
*** 18,23 ****
--- 18,24 ----
/* GUC variables */
extern bool autovacuum_start_daemon;
extern int autovacuum_max_workers;
+ extern int autovacuum_work_mem;
extern int autovacuum_naptime;
extern int autovacuum_vac_thresh;
extern double autovacuum_vac_scale;