Fix incorrect memory context switch in COPY TO execution

michaelpq · michaelpq · commit dc084d7c730c · 2022-01-29T10:22:42.000+09:00
c532d15 has split the logic of COPY commands into multiple files, one change being to move the internals of BeginCopy() to BeginCopyTo(). Originally the code was written so as we'd switch back-and-forth between the current execution memory context and the dedicated memory context for the COPY command, and this refactoring has introduced an extra switch to the current memory context from the COPY context once BeginCopyTo() is done with the past logic coming from BeginCopy(). The code was correctly doing the analyze, rewrite and planning phases in the COPY context, but it was not assigning "copy_file" (FILE* used when copying to a source file) and "filename" in the COPY context, making the COPY status data inconsistent. Author: Bharath Rupireddy Reviewed-by: Japin Li Discussion: https://postgr.es/m/CALj2ACWvVa69foi9jhHFY=2BuHxAoYboyE+vXQTARwxZcJnVrQ@mail.gmail.com Backpatch-through: 14
diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c
@@ -657,8 +657,6 @@ BeginCopyTo(ParseState *pstate,
 
 	cstate->copy_dest = COPY_FILE;	/* default */
 
-	MemoryContextSwitchTo(oldcontext);
-
 	if (pipe)
 	{
 		progress_vals[1] = PROGRESS_COPY_TYPE_PIPE;

Original file line number	Diff line number	Diff line change
`@@ -657,8 +657,6 @@ BeginCopyTo(ParseState *pstate,`
`657`	`657`
`658`	`658`	`cstate->copy_dest = COPY_FILE; /* default */`
`659`	`659`
`660`		`- MemoryContextSwitchTo(oldcontext);`
`661`		`-`
`662`	`660`	`if (pipe)`
`663`	`661`	`{`
`664`	`662`	`progress_vals[1] = PROGRESS_COPY_TYPE_PIPE;`