Introduces SQL functions to easily manipulate caching functionality. Closes #3442

pkg/db/db_common/functions.go

@@ -1,5 +1,7 @@
 package db_common
 
+import "github.com/turbot/steampipe/pkg/constants"
+
 // Functions is a list of SQLFunction objects that are installed in the db 'steampipe_internal' schema startup
 var Functions = []SQLFunction{
 	{
@@ -15,6 +17,36 @@ begin
 	output_pattern = replace(output_pattern, '?', '_');
 	return output_pattern;
 end;
+`,
+	},
+	{
+		Name:     constants.FunctionCacheSet,
+		Params:   map[string]string{"command": "text"},
+		Returns:  "void",
+		Language: "plpgsql",
+		Body: `
+begin
+	IF command = 'on' THEN
+		INSERT INTO steampipe_internal.steampipe_settings("name","value") VALUES ('cache','true');
+	ELSIF command = 'off' THEN
+		INSERT INTO steampipe_internal.steampipe_settings("name","value") VALUES ('cache','false');
+	ELSIF command = 'clear' THEN
+		INSERT INTO steampipe_internal.steampipe_settings("name","value") VALUES ('cache_clear_time','');
+	ELSE
+		RAISE EXCEPTION 'Unknown value % for set_cache - valid values are on, off and clear.', $1;
+	END IF;
+end;
+`,
+	},
+	{
+		Name:     constants.FunctionCacheSetTtl,
+		Params:   map[string]string{"duration": "int"},
+		Returns:  "void",
+		Language: "plpgsql",
+		Body: `
+begin
+	INSERT INTO steampipe_internal.steampipe_settings("name","value") VALUES ('cache_clear_time',duration);
+end;
 `,
 	},
 }