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PG-286: Small performance improvements. 

pgss_ExecutorEnd: Avoid unnecessary memset(plan_info, 0, ...).
We only use this object if the condition below is true, in which case we
already initialize all the fields in the object, also we now store the
plan string length (plan_info.plan_len) to avoid calling strlen on it
again later:
if (queryDesc->operation == CMD_SELECT && PGSM_QUERY_PLAN) {
... here we initialize plan_info

If the condition is false, then we pass a NULL PlanInfo* to the
pgss_store to avoid more unnecessary processing.

pgss_planner_hook: Similar, avoid memset(plan_info, 0, ...) this object
is not used here, so we pass NULL to pgss_store.

pg_get_application_name: Remove call to strlen, snprintf already give us
the calculated string length, so we just return it.

pg_get_client_addr: Cache localhost, avoid calling
ntohl(inet_addr("127.0.0.1")) all the time.

pgss_update_entry: Make use of PlanInfo->plan_len, avoiding a call to
strlen again.

intarray_get_datum: Init the string by setting the first byte to '\0'.
pull/184/head
Diego Fronza 2021-11-29 14:39:56 -03:00 committed by Hamid Akhtar
parent c21a3de00d
commit df89c3f4a3
2 changed files with 28 additions and 30 deletions
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53
pg_stat_monitor.c
View File

@ -656,14 +656,15 @@ pgss_ExecutorEnd(QueryDesc *queryDesc)
uint64 queryId = queryDesc->plannedstmt->queryId;
SysInfo sys_info;
PlanInfo plan_info;
PlanInfo *plan_ptr = NULL;
/* Extract the plan information in case of SELECT statment */
memset(&plan_info, 0, sizeof(PlanInfo));
/* Extract the plan information in case of SELECT statement */
if (queryDesc->operation == CMD_SELECT && PGSM_QUERY_PLAN)
{
MemoryContext mct = MemoryContextSwitchTo(TopMemoryContext);
snprintf(plan_info.plan_text, PLAN_TEXT_LEN, "%s", pgss_explain(queryDesc));
plan_info.planid = DatumGetUInt64(hash_any_extended((const unsigned char*)plan_info.plan_text, strlen(plan_info.plan_text), 0));
plan_info.plan_len = snprintf(plan_info.plan_text, PLAN_TEXT_LEN, "%s", pgss_explain(queryDesc));
plan_info.planid = DatumGetUInt64(hash_any_extended((const unsigned char*)plan_info.plan_text, plan_info.plan_len, 0));
plan_ptr = &plan_info;
MemoryContextSwitchTo(mct);
}
@ -682,7 +683,7 @@ pgss_ExecutorEnd(QueryDesc *queryDesc)
pgss_store(queryId, /* query id */
queryDesc->sourceText, /* query text */
&plan_info, /* PlanInfo */
plan_ptr, /* PlanInfo */
queryDesc->operation, /* CmdType */
&sys_info, /* SysInfo */
NULL, /* ErrorInfo */
@ -784,7 +785,6 @@ pgss_planner_hook(Query *parse, const char *query_string, int cursorOptions, Par
if (PGSM_TRACK_PLANNING && query_string && parse->queryId != UINT64CONST(0) && !IsParallelWorker())
{
PlanInfo plan_info;
instr_time start;
instr_time duration;
BufferUsage bufusage_start;
@ -792,7 +792,6 @@ pgss_planner_hook(Query *parse, const char *query_string, int cursorOptions, Par
WalUsage walusage_start;
WalUsage walusage;
memset(&plan_info, 0, sizeof(PlanInfo));
/* We need to track buffer usage as the planner can access them. */
bufusage_start = pgBufferUsage;
@ -836,7 +835,7 @@ pgss_planner_hook(Query *parse, const char *query_string, int cursorOptions, Par
WalUsageAccumDiff(&walusage, &pgWalUsage, &walusage_start);
pgss_store(parse->queryId, /* query id */
query_string, /* query */
&plan_info, /* PlanInfo */
NULL, /* PlanInfo */
parse->commandType, /* CmdType */
NULL, /* SysInfo */
NULL, /* ErrorInfo */
@ -1142,41 +1141,41 @@ pg_get_application_name(char *application_name)
if (!beentry)
return snprintf(application_name, APPLICATIONNAME_LEN, "%s", "postmaster");
snprintf(application_name, APPLICATIONNAME_LEN, "%s", beentry->st_appname);
return strlen(application_name);
return snprintf(application_name, APPLICATIONNAME_LEN, "%s", beentry->st_appname);
}
/*
* Store some statistics for a statement.
*
* If queryId is 0 then this is a utility statement and we should compute
* a suitable queryId internally.
*
* If jstate is not NULL then we're trying to create an entry for which
* we have no statistics as yet; we just want to record the normalized
*/
static uint
pg_get_client_addr(void)
{
PgBackendStatus *beentry = pg_get_backend_status();
char remote_host[NI_MAXHOST];
int ret;
static uint localhost = 0;
remote_host[0] = '\0';
if (!beentry)
return ntohl(inet_addr("127.0.0.1"));
memset(remote_host, 0x0, NI_MAXHOST);
ret = pg_getnameinfo_all(&beentry->st_clientaddr.addr,
beentry->st_clientaddr.salen,
remote_host, sizeof(remote_host),
NULL, 0,
NI_NUMERICHOST | NI_NUMERICSERV);
if (ret != 0)
return ntohl(inet_addr("127.0.0.1"));
{
if (localhost == 0)
localhost = ntohl(inet_addr("127.0.0.1"));
return localhost;
}
if (strcmp(remote_host, "[local]") == 0)
return ntohl(inet_addr("127.0.0.1"));
{
if (localhost == 0)
localhost = ntohl(inet_addr("127.0.0.1"));
return localhost;
}
return ntohl(inet_addr(remote_host));
}
@ -1204,7 +1203,7 @@ pgss_update_entry(pgssEntry *entry,
int message_len = error_info ? strlen (error_info->message) : 0;
int comments_len = comments ? strlen (comments) : 0;
int sqlcode_len = error_info ? strlen (error_info->sqlcode) : 0;
int plan_text_len = plan_info ? strlen (plan_info->plan_text) : 0;
int plan_text_len = plan_info ? plan_info->plan_len : 0;
/* volatile block */
@ -3018,18 +3017,16 @@ intarray_get_datum(int32 arr[], int len)
int j;
char str[1024];
char tmp[10];
bool first = true;
memset(str, 0, sizeof(str));
str[0] = '\0';
/* Need to calculate the actual size, and avoid unnessary memory usage */
for (j = 0; j < len; j++)
{
if (first)
if (!str[0])
{
snprintf(tmp, 10, "%d", arr[j]);
strcat(str,tmp);
first = false;
continue;
}
snprintf(tmp, 10, ",%d", arr[j]);

1
pg_stat_monitor.h
View File

@ -189,6 +189,7 @@ typedef struct PlanInfo
{
uint64 planid; /* plan identifier */
char plan_text[PLAN_TEXT_LEN]; /* plan text */
size_t plan_len; /* strlen(plan_text) */
} PlanInfo;
typedef struct pgssHashKey