branch: elpa/pg
commit 08e008f9c808f4dc99ffb950957dfe1718af90c3
Author: Eric Marsden <eric.mars...@risk-engineering.org>
Commit: Eric Marsden <eric.mars...@risk-engineering.org>
Modify SQL used to detect AlloyDB, for better cross-variant compatibility
---
pg.el | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/pg.el b/pg.el
index 7fb68c31b3..ce731c1211 100644
--- a/pg.el
+++ b/pg.el
@@ -497,12 +497,22 @@ Uses connection CON. The variant can be accessed by
`pgcon-server-variant'."
;; TODO: find a better detection method for ArcadeDB
((string-suffix-p "/main)" version)
(setf (pgcon-server-variant con) 'arcadedb))
- ;; A more expensive test is needed for Google AlloyDB. If this
parameter is defined,
- ;; the query will return "on" or "off" as a string, and if the
parameter is not defined
- ;; the query (second argument meaning no-error) will return
'((nil)).
- ((let ((res (pg-exec con "SELECT
current_setting('omni_disk_cache_enabled', true)")))
- (stringp (cl-first (pg-result res :tuple 0))))
- (setf (pgcon-server-variant con) 'alloydb))
+ ;; A more expensive test is needed for Google AlloyDB. If the
`omni_disk_cache_enabled'
+ ;; parameter is defined, the query will return "on" or "off" as a
string, and if the
+ ;; parameter is not defined the query (second argument meaning
no-error) will return
+ ;; '((nil)).
+ ;;
+ ;; We avoid using the two-argument version of the
current_setting() function, because
+ ;; it raises errors in various semi-compatible PostgreSQL
variants that only implement
+ ;; the single argument version. Instead, query the
+ ;; pg_settings table.
+ ;;
+ ;; "SELECT current_setting('omni_disk_cache_enabled', true)"
+ ((let* ((res (pg-exec-prepared con "SELECT setting FROM
pg_catalog.pg_settings WHERE name=$1"
+ `(("omni_disk_cache_enabled" .
"text"))))
+ (rows (pg-result res :tuples)))
+ (unless (null rows)
+ (setf (pgcon-server-variant con) 'alloydb))))
;; TODO: we could also detect CitusDB in the same way by checking
for citus.cluster_name
;; setting for example, but in practice it is very PostgreSQL
compatible so identifying
;; it as a variant doesn't seem mandatory.
