Hello Sergei,
> This patch correlates with my proposal
> "add session information column to pg_stat_statements"
> https://www.postgresql.org/message-id/3aa097d7-7c47-187b-5913-db8366cd4491%40gmail.com
> They both address the problem to identify the factors that make
> different execution plans for the same SQL statements. You are
> interested in the current settings that affect the execution plan, I'm
> concerned about historical data in pg_stat_statements. From my
> experience the most often offending settings are
> current_schemas/search_path and current_user. Please have in mind that
> probably the same approach that you will use to extend explain plan
> functionality will be eventually implemented to extend
> pg_stat_statements.
Possibly, although I don't have an ambition to export the GUCs into
pg_stat_statements in this patch. There's an issue with merging
different values of GUCs in different executions of a statement, and
it's unclear how to solve that.
> I think that the list of the GUCs that are reported
> by explain plan should be structured like JSON, something like
> extended_settings: { "current_schemas" : ["pg_catalog", "s1", "s2", "public"],
> "current_user" : "user1",
> "enable_nestloop" : "off",
> "work_mem" = "32MB"
> }
> It is less important for yours use case explain, but is important
> for pg_stat_statements case.
> The pg_stat_statements is often accessed by monitoring and reporting
> tools, and it will be a good idea to have > the data here in the
> structured and easily parsed format.
Yes, that's a good point. I think it's fine to keep the current format
for TEXT output, and use a structured format when the explain format is
set to json or yaml. That's what we do for data about Hash nodes, for
example (see show_hash_info).
So I've done that in the attached v5 of the patch, which now produces
something like this:
test=# explain (gucs, format json) select * from t;
QUERY PLAN
---------------------------------
[ +
{ +
"Plan": { +
"Node Type": "Seq Scan", +
"Parallel Aware": false, +
"Relation Name": "t", +
"Alias": "t", +
"Startup Cost": 0.00, +
"Total Cost": 61.00, +
"Plan Rows": 2550, +
"Plan Width": 4 +
}, +
"GUC": [ +
"cpu_tuple_cost": "0.02",+
"work_mem": "1GB" +
] +
} +
]
(1 row)
The one slightly annoying issue is that currently all the options are
formatted as text, including e.g. cpu_tuple_cost. That's because the GUC
options may have show hook, so I can't access the value directly (not
sure if there's an option around it).
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
diff --git a/contrib/auto_explain/auto_explain.c b/contrib/auto_explain/auto_explain.c
index 7b22927674..d3c4def942 100644
--- a/contrib/auto_explain/auto_explain.c
+++ b/contrib/auto_explain/auto_explain.c
@@ -28,6 +28,7 @@ static bool auto_explain_log_verbose = false;
static bool auto_explain_log_buffers = false;
static bool auto_explain_log_triggers = false;
static bool auto_explain_log_timing = true;
+static bool auto_explain_log_gucs = false;
static int auto_explain_log_format = EXPLAIN_FORMAT_TEXT;
static int auto_explain_log_level = LOG;
static bool auto_explain_log_nested_statements = false;
@@ -112,6 +113,17 @@ _PG_init(void)
NULL,
NULL);
+ DefineCustomBoolVariable("auto_explain.log_gucs",
+ "Print modified GUC values.",
+ NULL,
+ &auto_explain_log_gucs,
+ false,
+ PGC_SUSET,
+ 0,
+ NULL,
+ NULL,
+ NULL);
+
DefineCustomBoolVariable("auto_explain.log_verbose",
"Use EXPLAIN VERBOSE for plan logging.",
NULL,
@@ -356,6 +368,7 @@ explain_ExecutorEnd(QueryDesc *queryDesc)
es->timing = (es->analyze && auto_explain_log_timing);
es->summary = es->analyze;
es->format = auto_explain_log_format;
+ es->gucs = auto_explain_log_gucs;
ExplainBeginOutput(es);
ExplainQueryText(es, queryDesc);
diff --git a/doc/src/sgml/auto-explain.sgml b/doc/src/sgml/auto-explain.sgml
index 120b168d45..852c69b7bb 100644
--- a/doc/src/sgml/auto-explain.sgml
+++ b/doc/src/sgml/auto-explain.sgml
@@ -169,6 +169,23 @@ LOAD 'auto_explain';
</listitem>
</varlistentry>
+ <varlistentry>
+ <term>
+ <varname>auto_explain.log_gucs</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>auto_explain.log_gucs</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ <varname>auto_explain.log_gucs</varname> controls whether information
+ about modified configuration options are logged with the execution
+ plan. Only options modified at the database, user, client or session
+ level are considered modified. This parameter is off by default.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term>
<varname>auto_explain.log_format</varname> (<type>enum</type>)
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index ae7f038203..69ede5a5ef 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -30,6 +30,7 @@
#include "storage/bufmgr.h"
#include "tcop/tcopprot.h"
#include "utils/builtins.h"
+#include "utils/guc_tables.h"
#include "utils/json.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
@@ -163,6 +164,8 @@ ExplainQuery(ParseState *pstate, ExplainStmt *stmt, const char *queryString,
es->costs = defGetBoolean(opt);
else if (strcmp(opt->defname, "buffers") == 0)
es->buffers = defGetBoolean(opt);
+ else if (strcmp(opt->defname, "gucs") == 0)
+ es->gucs = defGetBoolean(opt);
else if (strcmp(opt->defname, "timing") == 0)
{
timing_set = true;
@@ -597,6 +600,68 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
ExplainCloseGroup("Query", NULL, true, es);
}
+static void
+ExplainShowGUC(ExplainState *es)
+{
+ int num;
+ struct config_generic **gucs;
+
+ /* bail out if GUC information not requested */
+ if (!es->gucs)
+ return;
+
+ gucs = get_explain_guc_options(&num);
+
+ /* also bail out of there are no options */
+ if (!num)
+ return;
+
+ if (es->format != EXPLAIN_FORMAT_TEXT)
+ {
+ int i;
+
+ ExplainOpenGroup("GUC", "GUC", false, es);
+
+ for (i = 0; i < num; i++)
+ {
+ char *setting;
+ struct config_generic *conf = gucs[i];
+
+ setting = GetConfigOptionByName(conf->name, NULL, true);
+
+ ExplainPropertyText(conf->name, setting, es);
+ }
+
+ ExplainCloseGroup("GUC", "GUC", false, es);
+ }
+ else
+ {
+ int i;
+ StringInfoData str;
+
+ initStringInfo(&str);
+
+ for (i = 0; i < num; i++)
+ {
+ char *setting;
+ struct config_generic *conf = gucs[i];
+
+ if (i > 0)
+ appendStringInfoString(&str, ", ");
+
+ setting = GetConfigOptionByName(conf->name, NULL, true);
+
+ if (setting)
+ appendStringInfo(&str, "%s = '%s'", conf->name, setting);
+ else
+ appendStringInfo(&str, "%s = NULL", conf->name);
+ }
+
+ if (num > 0)
+ ExplainPropertyText("GUCs", str.data, es);
+ }
+}
+
/*
* ExplainPrintPlan -
* convert a QueryDesc's plan tree to text and append it to es->str
@@ -634,6 +699,12 @@ ExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc)
if (IsA(ps, GatherState) &&((Gather *) ps->plan)->invisible)
ps = outerPlanState(ps);
ExplainNode(ps, NIL, NULL, NULL, es);
+
+ /*
+ * If requested, include information about GUC parameters that don't
+ * match the built-in defaults.
+ */
+ ExplainShowGUC(es);
}
/*
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index ae925c1650..bff9f182e9 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -862,7 +862,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of sequential-scan plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_seqscan,
true,
@@ -871,7 +872,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of index-scan plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_indexscan,
true,
@@ -880,7 +882,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_indexonlyscan", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of index-only-scan plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_indexonlyscan,
true,
@@ -889,7 +892,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of bitmap-scan plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_bitmapscan,
true,
@@ -898,7 +902,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of TID scan plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_tidscan,
true,
@@ -907,7 +912,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of explicit sort steps."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_sort,
true,
@@ -916,7 +922,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of hashed aggregation plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_hashagg,
true,
@@ -925,7 +932,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_material", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of materialization."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_material,
true,
@@ -934,7 +942,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of nested-loop join plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_nestloop,
true,
@@ -943,7 +952,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of merge join plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_mergejoin,
true,
@@ -952,7 +962,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of hash join plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_hashjoin,
true,
@@ -961,7 +972,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_gathermerge", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of gather merge plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_gathermerge,
true,
@@ -970,7 +982,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_partitionwise_join", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables partitionwise join."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_partitionwise_join,
false,
@@ -979,7 +992,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_partitionwise_aggregate", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables partitionwise aggregation and grouping."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_partitionwise_aggregate,
false,
@@ -988,7 +1002,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_parallel_append", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of parallel append plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_parallel_append,
true,
@@ -997,7 +1012,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"enable_parallel_hash", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of parallel hash plans."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&enable_parallel_hash,
true,
@@ -1008,7 +1024,8 @@ static struct config_bool ConfigureNamesBool[] =
gettext_noop("Enable plan-time and run-time partition pruning."),
gettext_noop("Allows the query planner and executor to compare partition "
"bounds to conditions in the query to determine which "
- "partitions must be scanned.")
+ "partitions must be scanned."),
+ GUC_EXPLAIN
},
&enable_partition_pruning,
true,
@@ -1018,7 +1035,8 @@ static struct config_bool ConfigureNamesBool[] =
{"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
gettext_noop("Enables genetic query optimization."),
gettext_noop("This algorithm attempts to do planning without "
- "exhaustive searching.")
+ "exhaustive searching."),
+ GUC_EXPLAIN
},
&enable_geqo,
true,
@@ -1591,7 +1609,7 @@ static struct config_bool ConfigureNamesBool[] =
"optimize_bounded_sort", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enable bounded sorting using heap sort."),
NULL,
- GUC_NOT_IN_SAMPLE
+ GUC_NOT_IN_SAMPLE | GUC_EXPLAIN
},
&optimize_bounded_sort,
true,
@@ -1782,7 +1800,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"parallel_leader_participation", PGC_USERSET, RESOURCES_ASYNCHRONOUS,
gettext_noop("Controls whether Gather and Gather Merge also run subplans."),
- gettext_noop("Should gather nodes also run subplans, or just gather tuples?")
+ gettext_noop("Should gather nodes also run subplans, or just gather tuples?"),
+ GUC_EXPLAIN
},
¶llel_leader_participation,
true,
@@ -1792,7 +1811,8 @@ static struct config_bool ConfigureNamesBool[] =
{
{"jit", PGC_USERSET, QUERY_TUNING_OTHER,
gettext_noop("Allow JIT compilation."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&jit_enabled,
true,
@@ -1921,7 +1941,8 @@ static struct config_int ConfigureNamesInt[] =
"are not collapsed."),
gettext_noop("The planner will merge subqueries into upper "
"queries if the resulting FROM list would have no more than "
- "this many items.")
+ "this many items."),
+ GUC_EXPLAIN
},
&from_collapse_limit,
8, 1, INT_MAX,
@@ -1933,7 +1954,8 @@ static struct config_int ConfigureNamesInt[] =
"constructs are not flattened."),
gettext_noop("The planner will flatten explicit JOIN "
"constructs into lists of FROM items whenever a "
- "list of no more than this many items would result.")
+ "list of no more than this many items would result."),
+ GUC_EXPLAIN
},
&join_collapse_limit,
8, 1, INT_MAX,
@@ -1942,7 +1964,8 @@ static struct config_int ConfigureNamesInt[] =
{
{"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&geqo_threshold,
12, 2, INT_MAX,
@@ -1951,7 +1974,8 @@ static struct config_int ConfigureNamesInt[] =
{
{"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&Geqo_effort,
DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT,
@@ -1960,7 +1984,8 @@ static struct config_int ConfigureNamesInt[] =
{
{"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
gettext_noop("GEQO: number of individuals in the population."),
- gettext_noop("Zero selects a suitable default value.")
+ gettext_noop("Zero selects a suitable default value."),
+ GUC_EXPLAIN
},
&Geqo_pool_size,
0, 0, INT_MAX,
@@ -1969,7 +1994,8 @@ static struct config_int ConfigureNamesInt[] =
{
{"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
gettext_noop("GEQO: number of iterations of the algorithm."),
- gettext_noop("Zero selects a suitable default value.")
+ gettext_noop("Zero selects a suitable default value."),
+ GUC_EXPLAIN
},
&Geqo_generations,
0, 0, INT_MAX,
@@ -2083,7 +2109,7 @@ static struct config_int ConfigureNamesInt[] =
{"temp_buffers", PGC_USERSET, RESOURCES_MEM,
gettext_noop("Sets the maximum number of temporary buffers used by each session."),
NULL,
- GUC_UNIT_BLOCKS
+ GUC_UNIT_BLOCKS | GUC_EXPLAIN
},
&num_temp_buffers,
1024, 100, INT_MAX / 2,
@@ -2150,7 +2176,7 @@ static struct config_int ConfigureNamesInt[] =
gettext_noop("This much memory can be used by each internal "
"sort operation and hash table before switching to "
"temporary disk files."),
- GUC_UNIT_KB
+ GUC_UNIT_KB | GUC_EXPLAIN
},
&work_mem,
4096, 64, MAX_KILOBYTES,
@@ -2701,7 +2727,8 @@ static struct config_int ConfigureNamesInt[] =
PGC_USERSET,
RESOURCES_ASYNCHRONOUS,
gettext_noop("Number of simultaneous requests that can be handled efficiently by the disk subsystem."),
- gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array.")
+ gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array."),
+ GUC_EXPLAIN
},
&effective_io_concurrency,
#ifdef USE_PREFETCH
@@ -2946,7 +2973,8 @@ static struct config_int ConfigureNamesInt[] =
{
{"max_parallel_workers_per_gather", PGC_USERSET, RESOURCES_ASYNCHRONOUS,
gettext_noop("Sets the maximum number of parallel processes per executor node."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&max_parallel_workers_per_gather,
2, 0, MAX_PARALLEL_WORKER_LIMIT,
@@ -2956,7 +2984,8 @@ static struct config_int ConfigureNamesInt[] =
{
{"max_parallel_workers", PGC_USERSET, RESOURCES_ASYNCHRONOUS,
gettext_noop("Sets the maximum number of parallel workers that can be active at one time."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&max_parallel_workers,
8, 0, MAX_PARALLEL_WORKER_LIMIT,
@@ -3046,7 +3075,7 @@ static struct config_int ConfigureNamesInt[] =
gettext_noop("Sets the planner's assumption about the total size of the data caches."),
gettext_noop("That is, the total size of the caches (kernel cache and shared buffers) used for PostgreSQL data files. "
"This is measured in disk pages, which are normally 8 kB each."),
- GUC_UNIT_BLOCKS,
+ GUC_UNIT_BLOCKS | GUC_EXPLAIN,
},
&effective_cache_size,
DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX,
@@ -3057,7 +3086,7 @@ static struct config_int ConfigureNamesInt[] =
{"min_parallel_table_scan_size", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Sets the minimum amount of table data for a parallel scan."),
gettext_noop("If the planner estimates that it will read a number of table pages too small to reach this limit, a parallel scan will not be considered."),
- GUC_UNIT_BLOCKS,
+ GUC_UNIT_BLOCKS | GUC_EXPLAIN,
},
&min_parallel_table_scan_size,
(8 * 1024 * 1024) / BLCKSZ, 0, INT_MAX / 3,
@@ -3068,7 +3097,7 @@ static struct config_int ConfigureNamesInt[] =
{"min_parallel_index_scan_size", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Sets the minimum amount of index data for a parallel scan."),
gettext_noop("If the planner estimates that it will read a number of index pages too small to reach this limit, a parallel scan will not be considered."),
- GUC_UNIT_BLOCKS,
+ GUC_UNIT_BLOCKS | GUC_EXPLAIN,
},
&min_parallel_index_scan_size,
(512 * 1024) / BLCKSZ, 0, INT_MAX / 3,
@@ -3133,7 +3162,8 @@ static struct config_real ConfigureNamesReal[] =
{"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Sets the planner's estimate of the cost of a "
"sequentially fetched disk page."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&seq_page_cost,
DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX,
@@ -3143,7 +3173,8 @@ static struct config_real ConfigureNamesReal[] =
{"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Sets the planner's estimate of the cost of a "
"nonsequentially fetched disk page."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&random_page_cost,
DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX,
@@ -3153,7 +3184,8 @@ static struct config_real ConfigureNamesReal[] =
{"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Sets the planner's estimate of the cost of "
"processing each tuple (row)."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&cpu_tuple_cost,
DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX,
@@ -3163,7 +3195,8 @@ static struct config_real ConfigureNamesReal[] =
{"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Sets the planner's estimate of the cost of "
"processing each index entry during an index scan."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&cpu_index_tuple_cost,
DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX,
@@ -3173,7 +3206,8 @@ static struct config_real ConfigureNamesReal[] =
{"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Sets the planner's estimate of the cost of "
"processing each operator or function call."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&cpu_operator_cost,
DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX,
@@ -3183,7 +3217,8 @@ static struct config_real ConfigureNamesReal[] =
{"parallel_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Sets the planner's estimate of the cost of "
"passing each tuple (row) from worker to master backend."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
¶llel_tuple_cost,
DEFAULT_PARALLEL_TUPLE_COST, 0, DBL_MAX,
@@ -3193,7 +3228,8 @@ static struct config_real ConfigureNamesReal[] =
{"parallel_setup_cost", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Sets the planner's estimate of the cost of "
"starting up worker processes for parallel query."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
¶llel_setup_cost,
DEFAULT_PARALLEL_SETUP_COST, 0, DBL_MAX,
@@ -3203,7 +3239,8 @@ static struct config_real ConfigureNamesReal[] =
{
{"jit_above_cost", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Perform JIT compilation if query is more expensive."),
- gettext_noop("-1 disables JIT compilation.")
+ gettext_noop("-1 disables JIT compilation."),
+ GUC_EXPLAIN
},
&jit_above_cost,
100000, -1, DBL_MAX,
@@ -3213,7 +3250,8 @@ static struct config_real ConfigureNamesReal[] =
{
{"jit_optimize_above_cost", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Optimize JITed functions if query is more expensive."),
- gettext_noop("-1 disables optimization.")
+ gettext_noop("-1 disables optimization."),
+ GUC_EXPLAIN
},
&jit_optimize_above_cost,
500000, -1, DBL_MAX,
@@ -3223,7 +3261,8 @@ static struct config_real ConfigureNamesReal[] =
{
{"jit_inline_above_cost", PGC_USERSET, QUERY_TUNING_COST,
gettext_noop("Perform JIT inlining if query is more expensive."),
- gettext_noop("-1 disables inlining.")
+ gettext_noop("-1 disables inlining."),
+ GUC_EXPLAIN
},
&jit_inline_above_cost,
500000, -1, DBL_MAX,
@@ -3234,7 +3273,8 @@ static struct config_real ConfigureNamesReal[] =
{"cursor_tuple_fraction", PGC_USERSET, QUERY_TUNING_OTHER,
gettext_noop("Sets the planner's estimate of the fraction of "
"a cursor's rows that will be retrieved."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&cursor_tuple_fraction,
DEFAULT_CURSOR_TUPLE_FRACTION, 0.0, 1.0,
@@ -3244,7 +3284,8 @@ static struct config_real ConfigureNamesReal[] =
{
{"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
gettext_noop("GEQO: selective pressure within the population."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&Geqo_selection_bias,
DEFAULT_GEQO_SELECTION_BIAS,
@@ -3254,7 +3295,8 @@ static struct config_real ConfigureNamesReal[] =
{
{"geqo_seed", PGC_USERSET, QUERY_TUNING_GEQO,
gettext_noop("GEQO: seed for random path selection."),
- NULL
+ NULL,
+ GUC_EXPLAIN
},
&Geqo_seed,
0.0, 0.0, 1.0,
@@ -3669,7 +3711,7 @@ static struct config_string ConfigureNamesString[] =
{"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the schema search order for names that are not schema-qualified."),
NULL,
- GUC_LIST_INPUT | GUC_LIST_QUOTE
+ GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_EXPLAIN
},
&namespace_search_path,
"\"$user\", public",
@@ -4122,7 +4164,8 @@ static struct config_enum ConfigureNamesEnum[] =
{"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
gettext_noop("Enables the planner to use constraints to optimize queries."),
gettext_noop("Table scans will be skipped if their constraints"
- " guarantee that no rows match the query.")
+ " guarantee that no rows match the query."),
+ GUC_EXPLAIN
},
&constraint_exclusion,
CONSTRAINT_EXCLUSION_PARTITION, constraint_exclusion_options,
@@ -4348,7 +4391,8 @@ static struct config_enum ConfigureNamesEnum[] =
{
{"force_parallel_mode", PGC_USERSET, QUERY_TUNING_OTHER,
gettext_noop("Forces use of parallel query facilities."),
- gettext_noop("If possible, run query using a parallel worker and with parallel restrictions.")
+ gettext_noop("If possible, run query using a parallel worker and with parallel restrictions."),
+ GUC_EXPLAIN
},
&force_parallel_mode,
FORCE_PARALLEL_OFF, force_parallel_mode_options,
@@ -4372,7 +4416,8 @@ static struct config_enum ConfigureNamesEnum[] =
gettext_noop("Controls the planner's selection of custom or generic plan."),
gettext_noop("Prepared statements can have custom and generic plans, and the planner "
"will attempt to choose which is better. This can be set to override "
- "the default behavior.")
+ "the default behavior."),
+ GUC_EXPLAIN
},
&plan_cache_mode,
PLAN_CACHE_MODE_AUTO, plan_cache_mode_options,
@@ -8556,6 +8601,86 @@ ShowAllGUCConfig(DestReceiver *dest)
end_tup_output(tstate);
}
+struct config_generic **
+get_explain_guc_options(int *num)
+{
+ int i;
+ struct config_generic **result;
+
+ *num = 0;
+ result = palloc(sizeof(struct config_generic *) * num_guc_variables);
+
+ for (i = 0; i < num_guc_variables; i++)
+ {
+ bool modified;
+ struct config_generic *conf = guc_variables[i];
+
+ /* return only options visible to the user */
+ if ((conf->flags & GUC_NO_SHOW_ALL) ||
+ ((conf->flags & GUC_SUPERUSER_ONLY) &&
+ !is_member_of_role(GetUserId(), DEFAULT_ROLE_READ_ALL_SETTINGS)))
+ continue;
+
+ /* only parameters explicitly marked for inclusion in explain */
+ if (!(conf->flags & GUC_EXPLAIN))
+ continue;
+
+ /* return only options that were modified (w.r.t. config file) */
+ modified = false;
+
+ switch (conf->vartype)
+ {
+ case PGC_BOOL:
+ {
+ struct config_bool *lconf = (struct config_bool *) conf;
+ modified = (lconf->boot_val != *(lconf->variable));
+ }
+ break;
+
+ case PGC_INT:
+ {
+ struct config_int *lconf = (struct config_int *) conf;
+ modified = (lconf->boot_val != *(lconf->variable));
+ }
+ break;
+
+ case PGC_REAL:
+ {
+ struct config_real *lconf = (struct config_real *) conf;
+ modified = (lconf->boot_val != *(lconf->variable));
+ }
+ break;
+
+ case PGC_STRING:
+ {
+ struct config_string *lconf = (struct config_string *) conf;
+ modified = (strcmp(lconf->boot_val, *(lconf->variable)) != 0);
+ }
+ break;
+
+ case PGC_ENUM:
+ {
+ struct config_enum *lconf = (struct config_enum *) conf;
+ modified = (lconf->boot_val != *(lconf->variable));
+ }
+ break;
+
+ default:
+ elog(ERROR, "unexcpected GUC type: %d", conf->vartype);
+ }
+
+ /* skip GUC variables that match the built-in default */
+ if (!modified)
+ continue;
+
+ /* assign to the values array */
+ result[*num] = conf;
+ *num = *num + 1;
+ }
+
+ return result;
+}
+
/*
* Return GUC variable value by name; optionally return canonical form of
* name. If the GUC is unset, then throw an error unless missing_ok is true,
diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
index e8854db459..364aacd5c2 100644
--- a/src/include/commands/explain.h
+++ b/src/include/commands/explain.h
@@ -35,6 +35,7 @@ typedef struct ExplainState
bool buffers; /* print buffer usage */
bool timing; /* print detailed node timing */
bool summary; /* print total planning and execution timing */
+ bool gucs; /* print modified GUCs */
ExplainFormat format; /* output format */
/* state for output formatting --- not reset for each new plan tree */
int indent; /* current indentation level */
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index c07e7b945e..90ef3889ae 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -227,6 +227,8 @@ typedef enum
#define GUC_UNIT_MIN 0x30000 /* value is in minutes */
#define GUC_UNIT_TIME 0xF0000 /* mask for time-related units */
+#define GUC_EXPLAIN 0x100000 /* include in explain */
+
#define GUC_UNIT (GUC_UNIT_MEMORY | GUC_UNIT_TIME)
diff --git a/src/include/utils/guc_tables.h b/src/include/utils/guc_tables.h
index a0970b2e1c..2a74b30b2f 100644
--- a/src/include/utils/guc_tables.h
+++ b/src/include/utils/guc_tables.h
@@ -267,5 +267,6 @@ extern void build_guc_variables(void);
extern const char *config_enum_lookup_by_value(struct config_enum *record, int val);
extern bool config_enum_lookup_by_name(struct config_enum *record,
const char *value, int *retval);
+extern struct config_generic **get_explain_guc_options(int *num);
#endif /* GUC_TABLES_H */
