fix: MySQL/Postgress max_idle_conn default was wrongly set to zero, which does not mean unlimited but zero, which in practice disables connection pooling, not good. now max idle conn is set to golang's default which is 2, fixes #8513

vendor/github.com/lib/pq/doc.go

@@ -5,8 +5,9 @@ In most cases clients will use the database/sql package instead of
 using this package directly. For example:
 
 	import (
-		_ "github.com/lib/pq"
 		"database/sql"
+
+		_ "github.com/lib/pq"
 	)
 
 	func main() {
@@ -85,9 +86,13 @@ variables not supported by pq are set, pq will panic during connection
 establishment.  Environment variables have a lower precedence than explicitly
 provided connection parameters.
 
+The pgpass mechanism as described in http://www.postgresql.org/docs/current/static/libpq-pgpass.html
+is supported, but on Windows PGPASSFILE must be specified explicitly.
+
 
 Queries
 
+
 database/sql does not dictate any specific format for parameter
 markers in query strings, and pq uses the Postgres-native ordinal markers,
 as shown above. The same marker can be reused for the same parameter:
@@ -111,8 +116,29 @@ For more details on RETURNING, see the Postgres documentation:
 
 For additional instructions on querying see the documentation for the database/sql package.
 
+
+Data Types
+
+
+Parameters pass through driver.DefaultParameterConverter before they are handled
+by this package. When the binary_parameters connection option is enabled,
+[]byte values are sent directly to the backend as data in binary format.
+
+This package returns the following types for values from the PostgreSQL backend:
+
+	- integer types smallint, integer, and bigint are returned as int64
+	- floating-point types real and double precision are returned as float64
+	- character types char, varchar, and text are returned as string
+	- temporal types date, time, timetz, timestamp, and timestamptz are returned as time.Time
+	- the boolean type is returned as bool
+	- the bytea type is returned as []byte
+
+All other types are returned directly from the backend as []byte values in text format.
+
+
 Errors
 
+
 pq may return errors of type *pq.Error which can be interrogated for error details:
 
         if err, ok := err.(*pq.Error); ok {