Add some words of caution to elog.c.

robertmhaas · robertmhaas · commit f196738534ba · 2011-02-17T10:29:42.000-05:00
Stephen Frost, somewhat rewritten by me
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
@@ -3,6 +3,12 @@
  * elog.c
  *	  error logging and reporting
  *
+ * Because of the extremely high rate at which log messages can be generated,
+ * we need to be mindful of the performance cost of obtaining any information
+ * that may be logged.  Also, it's important to keep in mind that this code may
+ * get called from within an aborted transaction, in which case operations
+ * such as syscache lookups are unsafe.
+ *
  * Some notes about recursion and errors during error processing:
  *
  * We need to be robust about recursive-error scenarios --- for example,

Original file line number	Diff line number	Diff line change
`@@ -3,6 +3,12 @@`
`3`	`3`	`* elog.c`
`4`	`4`	`* error logging and reporting`
`5`	`5`	`*`
	`6`	`+ * Because of the extremely high rate at which log messages can be generated,`
	`7`	`+ * we need to be mindful of the performance cost of obtaining any information`
	`8`	`+ * that may be logged. Also, it's important to keep in mind that this code may`
	`9`	`+ * get called from within an aborted transaction, in which case operations`
	`10`	`+ * such as syscache lookups are unsafe.`
	`11`	`+ *`
`6`	`12`	`* Some notes about recursion and errors during error processing:`
`7`	`13`	`*`
`8`	`14`	`* We need to be robust about recursive-error scenarios --- for example,`