SQL Expressions: Add setting to limit length of query (#110165)

sql_expression_query_length_limit

Set the maximum length of a SQL query that can be used in a SQL expression. Default is 10000 characters. A setting of 0 means no limit.

pkg/setting/setting.go

@@ -441,6 +441,9 @@ type Cfg struct {
 	// SQLExpressionOutputCellLimit is the maximum number of cells (rows × columns) that can be outputted by a SQL expression.
 	SQLExpressionOutputCellLimit int64
 
+	// SQLExpressionQueryLengthLimit is the maximum length of a SQL query that can be used in a SQL expression.
+	SQLExpressionQueryLengthLimit int64
+
 	// SQLExpressionTimeoutSeconds is the duration a SQL expression will run before timing out
 	SQLExpressionTimeout time.Duration
 
@@ -830,6 +833,7 @@ func (cfg *Cfg) readExpressionsSettings() {
 	cfg.SQLExpressionCellLimit = expressions.Key("sql_expression_cell_limit").MustInt64(100000)
 	cfg.SQLExpressionOutputCellLimit = expressions.Key("sql_expression_output_cell_limit").MustInt64(100000)
 	cfg.SQLExpressionTimeout = expressions.Key("sql_expression_timeout").MustDuration(time.Second * 10)
+	cfg.SQLExpressionQueryLengthLimit = expressions.Key("sql_expression_query_length_limit").MustInt64(10000)
 }
 
 type AnnotationCleanupSettings struct {