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pg_mon.c
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pg_mon.c
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/* -------------------------------------------------------------------------
*
* pg_mon.c
*
* Copyright (c) 2010-2019, PostgreSQL Global Development Group
*
* IDENTIFICATION
* contrib/pg_mon/pg_mon.c
* -------------------------------------------------------------------------
*/
#include <postgres.h>
#include <limits.h>
#include <miscadmin.h>
#include "storage/lwlock.h"
#include "storage/ipc.h"
#include "storage/shmem.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
#include "utils/tuplestore.h"
#include "funcapi.h"
#include "commands/explain.h"
#include "executor/instrument.h"
#include "utils/guc.h"
#include "nodes/plannodes.h"
#if PG_VERSION_NUM >= 130000
#include "common/hashfn.h"
#include "catalog/pg_type_d.h"
#else
#include "utils/hashutils.h"
#include "catalog/pg_type.h"
#endif
#include "mb/pg_wchar.h"
#include "utils/rel.h"
#include "utils/lsyscache.h"
#include "utils/builtins.h"
#include "nodes/plannodes.h"
#include "parser/parsetree.h"
#include "storage/spin.h"
#include "tcop/utility.h"
Datum pg_mon(PG_FUNCTION_ARGS);
Datum pg_mon_reset(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(pg_mon);
PG_FUNCTION_INFO_V1(pg_mon_reset);
PG_MODULE_MAGIC;
/* GUC variables */
static bool CONFIG_PLAN_INFO_IMMEDIATE = false;
static bool CONFIG_PLAN_INFO_DISABLE = false;
static bool CONFIG_LOG_NEW_QUERY = true;
static int MON_HT_SIZE = 5000;
#define MON_COLS 20
#define NUMBUCKETS 30
#define ROWNUMBUCKETS 20
#define MAX_TABLES 30
/*
* Record for a query.
*/
typedef struct mon_rec
{
int64 queryid;
double current_total_time;
double first_tuple_time;
double current_expected_rows;
double current_actual_rows;
bool is_parallel;
bool ModifyTable;
Oid seq_scans[MAX_TABLES];
Oid index_scans[MAX_TABLES];
Oid bitmap_scans[MAX_TABLES];
NameData other_scan;
int NestedLoopJoin ;
int HashJoin;
int MergeJoin;
int64 query_time_buckets[NUMBUCKETS];
int64 query_time_freq[NUMBUCKETS];
int64 actual_row_buckets[ROWNUMBUCKETS];
int64 actual_row_freq[ROWNUMBUCKETS];
int64 est_row_buckets[ROWNUMBUCKETS];
int64 est_row_freq[ROWNUMBUCKETS];
slock_t mutex;
}mon_rec;
/* Current nesting depth of ExecutorRun calls */
static int nesting_level = 0;
extern void _PG_init(void);
extern void _PG_fini(void);
/* LWlock to mange the reading and writing the hash table. */
LWLock *mon_lock;
typedef enum AddHist{
QUERY_TIME,
ACTUAL_ROWS,
EST_ROWS
} AddHist;
/* Saved hook values in case of unload */
static ExecutorStart_hook_type prev_ExecutorStart = NULL;
static ExecutorRun_hook_type prev_ExecutorRun = NULL;
static ExecutorFinish_hook_type prev_ExecutorFinish = NULL;
static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
static ProcessUtility_hook_type prev_ProcessUtility = NULL;
static void pgmon_ExecutorStart(QueryDesc *queryDesc, int eflags);
static void pgmon_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction,
uint64 count, bool execute_once);
static void pgmon_ExecutorFinish(QueryDesc *queryDesc);
static void pgmon_ExecutorEnd(QueryDesc *queryDesc);
static void pgmon_plan_store(QueryDesc *queryDesc);
static void pgmon_exec_store(QueryDesc *queryDesc);
#if PG_VERSION_NUM < 130000
static void PU_hook(PlannedStmt *pstmt, const char *queryString,
ProcessUtilityContext context, ParamListInfo params,
QueryEnvironment *queryEnv,
DestReceiver *dest, char *completionTag);
#define _PU_HOOK \
static void PU_hook(PlannedStmt *pstmt, const char *queryString,\
ProcessUtilityContext context, ParamListInfo params, \
QueryEnvironment *queryEnv, \
DestReceiver *dest, char *completionTag)
#define _prev_hook \
prev_ProcessUtility(pstmt, queryString, context, params, queryEnv, dest, completionTag)
#define _standard_ProcessUtility \
standard_ProcessUtility(pstmt, queryString, context, params, queryEnv, dest, completionTag)
#elif PG_VERSION_NUM >= 130000 && PG_VERSION_NUM < 140000
static void PU_hook(PlannedStmt *pstmt, const char *queryString,
ProcessUtilityContext context, ParamListInfo params,
QueryEnvironment *queryEnv,
DestReceiver *dest, QueryCompletion *qc);
#define _PU_HOOK \
static void PU_hook(PlannedStmt *pstmt, const char *queryString,\
ProcessUtilityContext context, ParamListInfo params, \
QueryEnvironment *queryEnv, \
DestReceiver *dest, QueryCompletion *qc)
#define _prev_hook \
prev_ProcessUtility(pstmt, queryString, context, params, queryEnv, dest, qc)
#define _standard_ProcessUtility \
standard_ProcessUtility(pstmt, queryString, context, params, queryEnv, dest, qc)
#else
static void PU_hook(PlannedStmt *pstmt, const char *queryString,
bool readOnlyTree,
ProcessUtilityContext context, ParamListInfo params,
QueryEnvironment *queryEnv,
DestReceiver *dest, QueryCompletion *qc);
#define _PU_HOOK \
static void PU_hook(PlannedStmt *pstmt, const char *queryString, bool readOnlyTree, \
ProcessUtilityContext context, ParamListInfo params, \
QueryEnvironment *queryEnv, \
DestReceiver *dest, QueryCompletion *qc)
#define _prev_hook \
prev_ProcessUtility(pstmt, queryString, readOnlyTree, context, params, queryEnv, dest, qc)
#define _standard_ProcessUtility \
standard_ProcessUtility(pstmt, queryString, readOnlyTree, context, params, queryEnv, dest, qc)
#endif
/* Saved hook values in case of unload */
static shmem_startup_hook_type prev_shmem_startup_hook = NULL;
static void shmem_shutdown(int code, Datum arg);
static void plan_tree_traversal(QueryDesc *query, Plan *plan, mon_rec *entry);
static void update_histogram(volatile mon_rec *entry, AddHist);
static void pg_mon_reset_internal(void);
static mon_rec * create_or_get_entry(mon_rec temp_entry, int64 queryId, QueryDesc *queryDesc);
static void scan_info(Plan *subplan, mon_rec *entry, QueryDesc *queryDesc);
static const char * scan_string(NodeTag type);
/* Hash table in the shared memory */
static HTAB *mon_ht;
/* Bucket boundaries for the histogram in ms, from 5 ms to 1 minute */
static int64 bucket_bounds[NUMBUCKETS] = {
1, 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80,
90, 100, 200, 300, 400, 500, 600, 700, 1000,
2000, 3000, 5000, 7000, 10000, 20000, 30000,
50000, 60000
};
static int64 row_bucket_bounds[ROWNUMBUCKETS] = {
1, 5, 10, 50, 100, 200, 300, 400, 500,
1000, 2000, 3000, 4000, 5000, 10000,
30000, 50000, 70000, 100000, 1000000
};
/*
* Keep a temporary record to store the plan information of the
* current query
*/
static mon_rec temp_entry;
/*
* shmem_startup hook: allocate and attach to shared memory,
*/
static void
shmem_startup(void)
{
HASHCTL info;
if (prev_shmem_startup_hook)
prev_shmem_startup_hook();
mon_ht = NULL;
/*
* Create or attach to the shared memory state, including hash table
*/
LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
memset(&info, 0, sizeof(info));
info.keysize = sizeof(uint32);
info.entrysize = sizeof(mon_rec);
#if PG_VERSION_NUM > 100000
info.hash = uint32_hash;
mon_ht = ShmemInitHash("mon_hash", MON_HT_SIZE, MON_HT_SIZE,
&info, HASH_ELEM | HASH_FUNCTION);
#else
mon_ht = ShmemInitHash("mon_hash", MON_HT_SIZE, MON_HT_SIZE,
&info, HASH_ELEM);
#endif
mon_lock = &(GetNamedLWLockTranche("mon_lock"))->lock;
LWLockRelease(AddinShmemInitLock);
/*
* If we're in the postmaster (or a standalone backend...), set up a shmem
* exit hook to dump the statistics to disk.
*/
if (!IsUnderPostmaster)
on_shmem_exit(shmem_shutdown, (Datum) 0);
}
/*
* shmem_shutdown hook
*
* Note: we don't bother with acquiring lock, because there should be no
* other processes running when this is called.
*/
static void
shmem_shutdown(int code, Datum arg)
{
mon_ht = NULL;
return;
}
/*
* Estimate shared memory space needed.
*/
static Size
qmon_memsize(void)
{
return hash_estimate_size(MON_HT_SIZE, sizeof(mon_rec));
}
/*
* Module Load Callback
*/
void
_PG_init(void)
{
if (!process_shared_preload_libraries_in_progress)
return;
DefineCustomIntVariable("pg_mon.max_statements",
"Sets the maximum number of statements tracked by pg_mon.",
NULL,
&MON_HT_SIZE,
5000,
100,
INT_MAX,
PGC_POSTMASTER,
0,
NULL,
NULL,
NULL);
DefineCustomBoolVariable("pg_mon.plan_info_immediate",
"Populate the plan time information immediately after planning phase.",
NULL,
&CONFIG_PLAN_INFO_IMMEDIATE,
CONFIG_PLAN_INFO_IMMEDIATE,
PGC_SUSET,
0,
NULL,
NULL,
NULL);
DefineCustomBoolVariable("pg_mon.plan_info_disable",
"Skip plan time information.",
NULL,
&CONFIG_PLAN_INFO_DISABLE,
CONFIG_PLAN_INFO_DISABLE,
PGC_SUSET,
0,
NULL,
NULL,
NULL);
DefineCustomBoolVariable("pg_mon.log_new_query",
"Log the new query.",
NULL,
&CONFIG_LOG_NEW_QUERY,
CONFIG_LOG_NEW_QUERY,
PGC_SUSET,
0,
NULL,
NULL,
NULL);
/*
* Request additional shared resources. (These are no-ops if we're not in
* the postmaster process.) We'll allocate or attach to the shared
* resources in *_shmem_startup().
*/
RequestAddinShmemSpace(qmon_memsize());
RequestNamedLWLockTranche("mon_lock", 1);
/* Install Hooks */
prev_shmem_startup_hook = shmem_startup_hook;
shmem_startup_hook = shmem_startup;
prev_ExecutorStart = ExecutorStart_hook;
ExecutorStart_hook = pgmon_ExecutorStart;
prev_ExecutorRun = ExecutorRun_hook;
ExecutorRun_hook = pgmon_ExecutorRun;
prev_ExecutorFinish = ExecutorFinish_hook;
ExecutorFinish_hook = pgmon_ExecutorFinish;
prev_ExecutorEnd = ExecutorEnd_hook;
ExecutorEnd_hook = pgmon_ExecutorEnd;
prev_ProcessUtility = ProcessUtility_hook;
ProcessUtility_hook = PU_hook;
}
/*
* Module unload callback
*/
void
_PG_fini(void)
{
/* Uninstall hooks. */
shmem_startup_hook = prev_shmem_startup_hook;
ExecutorStart_hook = prev_ExecutorStart;
ExecutorRun_hook = prev_ExecutorRun;
ExecutorFinish_hook = prev_ExecutorFinish;
ExecutorEnd_hook = prev_ExecutorEnd;
ProcessUtility_hook = prev_ProcessUtility;
}
/*
* ExecutorStart hook: start up logging if needed
*/
static void
pgmon_ExecutorStart(QueryDesc *queryDesc, int eflags)
{
if (prev_ExecutorStart)
prev_ExecutorStart(queryDesc, eflags);
else
standard_ExecutorStart(queryDesc, eflags);
if (queryDesc->plannedstmt->queryId != UINT64CONST(0) && nesting_level == 0)
{
/*
* Set up to track total elapsed time in ExecutorRun.Make sure the space
* is allocated in the per-query context so it will go away at ExecutorEnd.
*/
if(queryDesc->totaltime == NULL)
{
/*
* We need to be in right memory context before allocating. Similar
* to how it is done in other places, e.g. in pg_stat_statements,
* auto_explain, etc.
* https://github.com/postgres/postgres/blob/5f28b21eb3c5c2fb72c24608bc686acd7c9b113c/contrib/pg_stat_statements/pg_stat_statements.c#L1021
*/
MemoryContext oldcxt;
oldcxt = MemoryContextSwitchTo(queryDesc->estate->es_query_cxt);
#if PG_VERSION_NUM < 140000
queryDesc->totaltime = InstrAlloc(1, INSTRUMENT_ALL);
#else
queryDesc->totaltime = InstrAlloc(1, INSTRUMENT_ALL, false);
#endif
MemoryContextSwitchTo(oldcxt);
}
if (queryDesc->planstate->instrument == NULL)
{
/*
* We need to be in right memory context before allocating. Similar
* to how it is done in other places, e.g. ExecInitNode
* https://github.com/postgres/postgres/blob/5f28b21eb3c5c2fb72c24608bc686acd7c9b113c/src/backend/executor/execProcnode.c#L397
*/
MemoryContext oldcxt;
oldcxt = MemoryContextSwitchTo(queryDesc->estate->es_query_cxt);
#if PG_VERSION_NUM < 140000
queryDesc->planstate->instrument = InstrAlloc(1, INSTRUMENT_ALL);
#else
queryDesc->planstate->instrument = InstrAlloc(1, INSTRUMENT_ALL, false);
#endif
MemoryContextSwitchTo(oldcxt);
}
queryDesc->instrument_options |= INSTRUMENT_ROWS;
memset(&temp_entry, 0, sizeof(mon_rec));
temp_entry.queryid = queryDesc->plannedstmt->queryId;
/* Add the bucket boundaries for the entry */
memcpy(temp_entry.query_time_buckets, bucket_bounds, sizeof(bucket_bounds));
memcpy(temp_entry.actual_row_buckets, row_bucket_bounds, sizeof(row_bucket_bounds));
memcpy(temp_entry.est_row_buckets, row_bucket_bounds, sizeof(row_bucket_bounds));
if (!CONFIG_PLAN_INFO_DISABLE)
pgmon_plan_store(queryDesc);
}
}
/*
* ExecutorRun hook: all we need do is track nesting depth
*/
static void
pgmon_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction,
uint64 count, bool execute_once)
{
nesting_level++;
PG_TRY();
{
if (prev_ExecutorRun)
prev_ExecutorRun(queryDesc, direction, count, execute_once);
else
standard_ExecutorRun(queryDesc, direction, count, execute_once);
#if PG_VERSION_NUM < 130000
nesting_level--;
#endif
}
#if PG_VERSION_NUM < 130000
PG_CATCH();
{
nesting_level--;
PG_RE_THROW();
}
#else
PG_FINALLY();
{
nesting_level--;
}
#endif
PG_END_TRY();
}
/*
* ExecutorFinish hook: all we need do is track nesting depth
*/
static void
pgmon_ExecutorFinish(QueryDesc *queryDesc)
{
if (queryDesc->planstate->instrument && nesting_level == 0)
{
temp_entry.first_tuple_time = queryDesc->planstate->instrument->firsttuple * 1000;
}
nesting_level++;
PG_TRY();
{
if (prev_ExecutorFinish)
prev_ExecutorFinish(queryDesc);
else
standard_ExecutorFinish(queryDesc);
#if PG_VERSION_NUM < 130000
nesting_level--;
#endif
}
#if PG_VERSION_NUM < 130000
PG_CATCH();
{
nesting_level--;
PG_RE_THROW();
}
#else
PG_FINALLY();
{
nesting_level--;
}
#endif
PG_END_TRY();
}
/*
* ExecutorEnd hook: log results if needed
*/
static void
pgmon_ExecutorEnd(QueryDesc *queryDesc)
{
uint64 queryId = queryDesc->plannedstmt->queryId;
if (queryId != UINT64CONST(0) && queryDesc->totaltime && nesting_level == 0)
{
/*
* Make sure stats accumulation is done.
* (Note: it's okay if several levels of hook all do this.)
*/
InstrEndLoop(queryDesc->totaltime);
InstrEndLoop(queryDesc->planstate->instrument);
/* Save query information */
pgmon_exec_store(queryDesc);
}
if (prev_ExecutorEnd)
prev_ExecutorEnd(queryDesc);
else
standard_ExecutorEnd(queryDesc);
}
/*
* ProcessUtility hook
*/
_PU_HOOK
{
if (CONFIG_LOG_NEW_QUERY)
{
switch (nodeTag(pstmt->utilityStmt))
{
case T_AlterRoleStmt:
break;
default:
ereport(LOG, (errmsg("new query registered from pg_mon"), errhint("%s", queryString)));
break;
}
}
if (prev_ProcessUtility)
{
_prev_hook;
}
else
{
_standard_ProcessUtility;
}
}
static void
pgmon_plan_store(QueryDesc *queryDesc)
{
mon_rec *entry = NULL;
volatile mon_rec *e;
/* Safety check... */
if (!mon_ht)
return;
Assert(queryDesc != NULL);
if (!CONFIG_PLAN_INFO_DISABLE)
{
plan_tree_traversal(queryDesc, queryDesc->plannedstmt->planTree, &temp_entry);
temp_entry.current_expected_rows = queryDesc->planstate->plan->plan_rows;
}
/*
* If plan information is to be provided immediately, then take the
* lock here to update the information in hash table.
*/
if (CONFIG_PLAN_INFO_IMMEDIATE && !CONFIG_PLAN_INFO_DISABLE)
{
LWLockAcquire(mon_lock, LW_SHARED);
entry = create_or_get_entry(temp_entry, temp_entry.queryid, queryDesc);
e = (volatile mon_rec *) entry;
SpinLockAcquire(&e->mutex);
update_histogram(e, EST_ROWS);
SpinLockRelease(&e->mutex);
LWLockRelease(mon_lock);
}
}
static void
pgmon_exec_store(QueryDesc *queryDesc)
{
mon_rec *entry = NULL;
volatile mon_rec *e;
int64 queryId = queryDesc->plannedstmt->queryId;
bool is_present = false;
int i, j;
Assert(queryDesc!= NULL);
/* Safety check... */
if (!mon_ht)
return;
LWLockAcquire(mon_lock, LW_SHARED);
entry = create_or_get_entry(temp_entry, queryId, queryDesc);
e = (volatile mon_rec *) entry;
SpinLockAcquire(&e->mutex);
e->current_total_time = queryDesc->totaltime->total * 1000; //(in msec)
e->first_tuple_time = temp_entry.first_tuple_time;
update_histogram(e, QUERY_TIME);
e->current_actual_rows = queryDesc->totaltime->ntuples;
update_histogram(e, ACTUAL_ROWS);
/*
* If planning info is not already updated then only update
* estimated rows histogram.
*/
if (!CONFIG_PLAN_INFO_IMMEDIATE)
update_histogram(e, EST_ROWS);
/*
* If this query is already present in the hash table, then update the
* plan information of the query also. If the seq_scans, indexes, etc.
* used by the query are different from the previous view then add
* them to the entry here.
* However, if the number of seq_scans or index_scans has reached
* more than MAX_TABLES, then silently exit without adding.
*
* O(tables^2) in current loops may need sort aftert testing.
*/
if (!CONFIG_PLAN_INFO_DISABLE)
{
for (j = 0; j < MAX_TABLES && temp_entry.seq_scans[j] != 0; j++)
{
for (i = 0; i < MAX_TABLES && entry->seq_scans[i] != 0; i++)
{
if (temp_entry.seq_scans[j] == entry->seq_scans[i])
{
is_present = true;
break;
}
}
if (!is_present && i < MAX_TABLES)
{
entry->seq_scans[i] = temp_entry.seq_scans[j];
}
is_present = false;
}
for (j = 0; j < MAX_TABLES && temp_entry.index_scans[j] != 0; j++)
{
for (i = 0; i < MAX_TABLES && entry->index_scans[i] != 0; i++)
{
if (temp_entry.index_scans[j] == entry->index_scans[i])
{
is_present = true;
break;
}
}
if (!is_present && i < MAX_TABLES)
{
entry->index_scans[i] = temp_entry.index_scans[j];
}
is_present = false;
}
for (j = 0; j < MAX_TABLES && temp_entry.bitmap_scans[j] != 0; j++)
{
for (i = 0; i < MAX_TABLES && entry->bitmap_scans[i] != 0; i++)
{
if (temp_entry.bitmap_scans[j] == entry->bitmap_scans[i])
{
is_present = true;
break;
}
}
if (!is_present && i < MAX_TABLES)
{
entry->bitmap_scans[i] = temp_entry.bitmap_scans[j];
}
is_present = false;
}
if (entry->NestedLoopJoin < temp_entry.NestedLoopJoin)
entry->NestedLoopJoin = temp_entry.NestedLoopJoin;
if (entry->HashJoin < temp_entry.HashJoin)
entry->HashJoin = temp_entry.HashJoin;
if (entry->MergeJoin < temp_entry.MergeJoin)
entry->MergeJoin = temp_entry.MergeJoin;
}
SpinLockRelease(&e->mutex);
LWLockRelease(mon_lock);
}
/*
* Find the required hash table entry if not found then copy the
* contents of temp_entry, otherwise return the entry. The caller should have
* shared lock on hash_table which could be upgraded to exclusive mode, if new
* entry has to be added.
*/
static mon_rec * create_or_get_entry(mon_rec temp_entry, int64 queryId, QueryDesc *queryDesc)
{
mon_rec *entry = NULL;
bool found = false;
entry = (mon_rec *) hash_search(mon_ht, &queryId, HASH_FIND, &found);
if (!entry)
{
LWLockRelease(mon_lock);
LWLockAcquire(mon_lock, LW_EXCLUSIVE);
/*
* Check if the number of entries are exceeding the limit. Currently,
* we are handling this case by resetting the pg_mon view, but could be
* dealt more elegantly later, e.g. as in pg_stat_statetments remove
* the least used entries, etc.
*/
if (hash_get_num_entries(mon_ht) >= MON_HT_SIZE)
{
pg_mon_reset_internal();
}
entry = (mon_rec *) hash_search(mon_ht, &queryId, HASH_ENTER, &found);
if (!found)
{
*entry = temp_entry;
SpinLockInit(&entry->mutex);
/* Since this is a new query, log the query text */
if (CONFIG_LOG_NEW_QUERY)
{
ereport(LOG, (errmsg("new query registered from pg_mon"), errhint("%s", queryDesc->sourceText)));
}
}
}
return entry;
}
static void
plan_tree_traversal(QueryDesc *queryDesc, Plan *plan_node, mon_rec *entry)
{
#if PG_VERSION_NUM < 140000
ModifyTable *mplan;
ListCell *p;
#endif
/* Iterate through the plan to find all the required nodes*/
if (plan_node != NULL)
{
switch(plan_node->type)
{
case T_SeqScan:
case T_IndexScan:
case T_IndexOnlyScan:
case T_BitmapIndexScan:
scan_info(plan_node, entry, queryDesc);
break;
case T_FunctionScan:
case T_SampleScan:
case T_TidScan:
case T_SubqueryScan:
case T_ValuesScan:
case T_TableFuncScan:
case T_CteScan:
case T_NamedTuplestoreScan:
case T_WorkTableScan:
case T_ForeignScan:
case T_CustomScan:
namestrcpy(&entry->other_scan, scan_string(plan_node->type));
break;
case T_NestLoop:
entry->NestedLoopJoin++;
break;
case T_MergeJoin:
entry->MergeJoin++;
break;
case T_HashJoin:
entry->HashJoin++;
break;
case T_Gather:
case T_GatherMerge:
entry->is_parallel = true;
break;
case T_ModifyTable:
entry->ModifyTable = true;
#if PG_VERSION_NUM < 140000
mplan =(ModifyTable *)plan_node;
foreach (p, mplan->plans){
Plan *subplan = (Plan *) lfirst (p);
if (subplan != NULL){
scan_info(subplan, entry, queryDesc);
}
}
#endif
break;
default:
break;
}
if (plan_node->lefttree)
plan_tree_traversal(queryDesc, plan_node->lefttree, entry);
if (plan_node->righttree)
plan_tree_traversal(queryDesc, plan_node->righttree, entry);
}
}
static void
scan_info(Plan *subplan, mon_rec *entry, QueryDesc *queryDesc)
{
bool found = false;
IndexScan *idx;
BitmapIndexScan *bidx;
Scan *scan;
RangeTblEntry *rte;
Index relid;
int i = 0;
switch(subplan->type)
{
case T_SeqScan:
scan = (Scan *)subplan;
relid = scan->scanrelid;
rte = rt_fetch(relid, queryDesc->plannedstmt->rtable);
for (i = 0; i < MAX_TABLES && entry->seq_scans[i] > 0;
i++)
{
if (entry->seq_scans[i] == rte->relid)
{
found = true;
break;
}
}
if (!found && i < MAX_TABLES)
entry->seq_scans[i] = rte->relid;
break;
case T_IndexScan:
case T_IndexOnlyScan:
idx = (IndexScan *)subplan;
for (i = 0; i < MAX_TABLES && entry->index_scans[i] > 0;
i++)
{
if (entry->index_scans[i] == idx->indexid)
{
found = true;
break;
}
}
if (!found && i < MAX_TABLES)
entry->index_scans[i] = idx->indexid;
break;
case T_BitmapIndexScan:
bidx = (BitmapIndexScan *)subplan;
for (i = 0; i < MAX_TABLES && entry->bitmap_scans[i] > 0;
i++)
{
if (entry->bitmap_scans[i] == bidx->indexid)
{
found = true;
break;
}
}
if (!found && i < MAX_TABLES)
entry->bitmap_scans[i] = bidx->indexid;
break;
default:
break;
}
}
/*
* This is called when user requests the pg_mon view.
*/
Datum
pg_mon(PG_FUNCTION_ARGS)
{
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
TupleDesc tupdesc;
Tuplestorestate *tupstore;
MemoryContext per_query_ctx;
MemoryContext oldcontext;
HASH_SEQ_STATUS status;
mon_rec *entry;
/* hash table must exist already */
if (!mon_ht)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("pg_mon must be loaded via shared_preload_libraries")));
/* Switch into long-lived context to construct returned data structures */
per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
oldcontext = MemoryContextSwitchTo(per_query_ctx);
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
tupstore = tuplestore_begin_heap(true, false, work_mem);
MemoryContextSwitchTo(oldcontext);
LWLockAcquire(mon_lock, LW_SHARED);
hash_seq_init(&status, mon_ht);
while ((entry = hash_seq_search(&status)) != NULL)
{
Datum *numdatums = (Datum *) palloc(NUMBUCKETS * sizeof(Datum));
Datum *rownumdatums = (Datum *) palloc(ROWNUMBUCKETS * sizeof(Datum));
Datum values[MON_COLS];
bool nulls[MON_COLS] = {0};
int i = 0, n, idx = 0, last_fill_bucket = 0;
ArrayType *arry = NULL;
memset(values, 0, sizeof(values));
memset(nulls, 0, sizeof(nulls));
values[i++] = Int64GetDatum(entry->queryid);
values[i++] = Float8GetDatumFast(entry->current_total_time);
values[i++] = Float8GetDatumFast(entry->first_tuple_time);
values[i++] = Float8GetDatumFast(entry->current_expected_rows);
values[i++] = Float8GetDatumFast(entry->current_actual_rows);
values[i++] = BoolGetDatum(entry->is_parallel);
values[i++] = BoolGetDatum(entry->ModifyTable);
if (!entry->ModifyTable && entry->seq_scans[0] == 0)
nulls[i++] = true;
else
{
Datum *datums = (Datum *) palloc(MAX_TABLES * sizeof(Datum));
ArrayType *arry;
int n = 0, idx = 0;
for (n = 0; n < MAX_TABLES && entry->seq_scans[n] != 0; n++)
datums[idx++] = ObjectIdGetDatum(&entry->seq_scans[n]);
arry = construct_array(datums, idx, OIDOID, sizeof(Oid), false, 'i');
values[i++] = PointerGetDatum(arry);
}
if (!entry->ModifyTable && entry->index_scans[0] == 0)
nulls[i++] = true;
else
{
Datum *datums = (Datum *) palloc(MAX_TABLES * sizeof(Datum));
ArrayType *arry;
int n = 0, idx = 0;
for (n = 0; n < MAX_TABLES && entry->index_scans[n] != 0; n++)
datums[idx++] = ObjectIdGetDatum(&entry->index_scans[n]);
arry = construct_array(datums, idx, OIDOID, sizeof(Oid), false, 'i');
values[i++] = PointerGetDatum(arry);
}
if (!entry->ModifyTable && entry->bitmap_scans[0] == 0)
nulls[i++] = true;
else
{
Datum *datums = (Datum *) palloc(MAX_TABLES * sizeof(Datum));
ArrayType *arry;
int n = 0, idx = 0;
for (n = 0; n < MAX_TABLES && entry->bitmap_scans[n] != 0; n++)
datums[idx++] = ObjectIdGetDatum(&entry->bitmap_scans[n]);
arry = construct_array(datums, idx, OIDOID, sizeof(Oid), false, 'i');
values[i++] = PointerGetDatum(arry);
}
values[i++] = NameGetDatum(&entry->other_scan);
values[i++] = Int32GetDatum(entry->NestedLoopJoin);
values[i++] = Int32GetDatum(entry->HashJoin);
values[i++] = Int32GetDatum(entry->MergeJoin);
for (n = NUMBUCKETS-1; n >= 0; n--)
{
if (entry->query_time_freq[n] > 0)
{
last_fill_bucket = n;
break;
}
}
for (n = 0; n <= last_fill_bucket; n++)
{
numdatums[idx++] = Int64GetDatum(entry->query_time_buckets[n]);
}
arry = construct_array(numdatums, idx, INT4OID, sizeof(int), true, 'i');
values[i++] = PointerGetDatum(arry);
for (n = 0, idx = 0; n <= last_fill_bucket; n++)
{
numdatums[idx++] = Int64GetDatum(entry->query_time_freq[n]);
}
arry = construct_array(numdatums, idx, INT4OID, sizeof(int), true, 'i');
values[i++] = PointerGetDatum(arry);
numdatums = NULL;
arry = NULL;
last_fill_bucket = 0;
for (n = ROWNUMBUCKETS-1; n >= 0; n--)
{
if (entry->actual_row_freq[n] > 0)
{
last_fill_bucket = n;
break;
}
}
for (n = 0, idx = 0; n <= last_fill_bucket; n++)
{
rownumdatums[idx++] = Int64GetDatum(entry->actual_row_buckets[n]);
}
arry = construct_array(rownumdatums, idx, INT4OID, sizeof(int), true, 'i');
values[i++] = PointerGetDatum(arry);