Merge #89020

89020: sql: turn plan sampling back on by default r=maryliag a=maryliag

This value was disabled by default on #88343
but brought visibility to a bug of statements not being properly trace when they should be on the first time. Since we might not be able to finish the proper fix before the cut on backports, I'm turning back on and a following commit can turn this back off and add the fix for the problem.

Release note (sql change): Turn the default value of `sql.metrics.statement_details.plan_collection.enabled` to `true`

Co-authored-by: Marylia Gutierrez <[email protected]>

Author: craig[bot]

docs/generated/settings/settings-for-tenants.txt

@@ -253,7 +253,7 @@ sql.metrics.statement_details.enabled	boolean	true	collect per-statement query s
 sql.metrics.statement_details.gateway_node.enabled	boolean	true	save the gateway node for each statement fingerprint. If false, the value will be stored as 0.
 sql.metrics.statement_details.index_recommendation_collection.enabled	boolean	true	generate an index recommendation for each fingerprint ID
 sql.metrics.statement_details.max_mem_reported_idx_recommendations	integer	5000	the maximum number of reported index recommendation info stored in memory
-sql.metrics.statement_details.plan_collection.enabled	boolean	false	periodically save a logical plan for each fingerprint
+sql.metrics.statement_details.plan_collection.enabled	boolean	true	periodically save a logical plan for each fingerprint
 sql.metrics.statement_details.plan_collection.period	duration	5m0s	the time until a new logical plan is collected
 sql.metrics.statement_details.threshold	duration	0s	minimum execution time to cause statement statistics to be collected. If configured, no transaction stats are collected.
 sql.metrics.transaction_details.enabled	boolean	true	collect per-application transaction statistics

docs/generated/settings/settings.html

@@ -187,7 +187,7 @@
 <tr><td><code>sql.metrics.statement_details.gateway_node.enabled</code></td><td>boolean</td><td><code>true</code></td><td>save the gateway node for each statement fingerprint. If false, the value will be stored as 0.</td></tr>
 <tr><td><code>sql.metrics.statement_details.index_recommendation_collection.enabled</code></td><td>boolean</td><td><code>true</code></td><td>generate an index recommendation for each fingerprint ID</td></tr>
 <tr><td><code>sql.metrics.statement_details.max_mem_reported_idx_recommendations</code></td><td>integer</td><td><code>5000</code></td><td>the maximum number of reported index recommendation info stored in memory</td></tr>
-<tr><td><code>sql.metrics.statement_details.plan_collection.enabled</code></td><td>boolean</td><td><code>false</code></td><td>periodically save a logical plan for each fingerprint</td></tr>
+<tr><td><code>sql.metrics.statement_details.plan_collection.enabled</code></td><td>boolean</td><td><code>true</code></td><td>periodically save a logical plan for each fingerprint</td></tr>
 <tr><td><code>sql.metrics.statement_details.plan_collection.period</code></td><td>duration</td><td><code>5m0s</code></td><td>the time until a new logical plan is collected</td></tr>
 <tr><td><code>sql.metrics.statement_details.threshold</code></td><td>duration</td><td><code>0s</code></td><td>minimum execution time to cause statement statistics to be collected. If configured, no transaction stats are collected.</td></tr>
 <tr><td><code>sql.metrics.transaction_details.enabled</code></td><td>boolean</td><td><code>true</code></td><td>collect per-application transaction statistics</td></tr>

pkg/sql/sqlstats/cluster_settings.go

@@ -65,7 +65,7 @@ var SampleLogicalPlans = settings.RegisterBoolSetting(
 	settings.TenantWritable,
 	"sql.metrics.statement_details.plan_collection.enabled",
 	"periodically save a logical plan for each fingerprint",
-	false,
+	true,
 ).WithPublic()
 
 // LogicalPlanCollectionPeriod specifies the interval between collections of