Refactor CopyFrom() in copyfrom.c.

This commit simplifies CopyFrom() by removing the unnecessary local variable
'skipped', which tracked the number of rows skipped due to on_error = 'ignore'.
That count is already handled by cstate->num_errors, so the 'skipped' variable
was redundant.

Additionally, the condition on_error != COPY_ON_ERROR_STOP is removed.
Since on_error == COPY_ON_ERROR_IGNORE is already checked, and on_error
only has two values (ignore and stop), the additional check was redundant
and made the logic harder to read. Seemingly this was introduced
in preparation for a future patch, but the current checks don’t offer
clear value and have been removed to improve readability.

Author: Atsushi Torikoshi
Reviewed-by: Masahiko Sawada, Fujii Masao
Discussion: https://postgr.es/m/ab59dad10490ea3734cf022b16c24cfd@oss.nttdata.com

diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
index 47879994f7848ccc87af86f733191f94265c3c35..9139a407858d48b3562654c84463f5827af3b407 100644 (file)
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -657,7 +657,6 @@ CopyFrom(CopyFromState cstate)
        CopyMultiInsertInfo multiInsertInfo = {0};      /* pacify compiler */
        int64           processed = 0;
        int64           excluded = 0;
-       int64           skipped = 0;
        bool            has_before_insert_row_trig;
        bool            has_instead_insert_row_trig;
        bool            leafpart_use_multi_insert = false;
@@ -1004,26 +1003,22 @@ CopyFrom(CopyFromState cstate)
                if (!NextCopyFrom(cstate, econtext, myslot->tts_values, myslot->tts_isnull))
                        break;
 
-               if (cstate->opts.on_error != COPY_ON_ERROR_STOP &&
+               if (cstate->opts.on_error == COPY_ON_ERROR_IGNORE &&
                        cstate->escontext->error_occurred)
                {
                        /*
-                        * Soft error occurred, skip this tuple and deal with error
-                        * information according to ON_ERROR.
+                        * Soft error occurred, skip this tuple and just make
+                        * ErrorSaveContext ready for the next NextCopyFrom. Since we
+                        * don't set details_wanted and error_data is not to be filled,
+                        * just resetting error_occurred is enough.
                         */
-                       if (cstate->opts.on_error == COPY_ON_ERROR_IGNORE)
-
-                               /*
-                                * Just make ErrorSaveContext ready for the next NextCopyFrom.
-                                * Since we don't set details_wanted and error_data is not to
-                                * be filled, just resetting error_occurred is enough.
-                                */
-                               cstate->escontext->error_occurred = false;
+                       cstate->escontext->error_occurred = false;
 
                        /* Report that this tuple was skipped by the ON_ERROR clause */
                        pgstat_progress_update_param(PROGRESS_COPY_TUPLES_SKIPPED,
-                                                                                ++skipped);
+                                                                                cstate->num_errors);
 
+                       /* Repeat NextCopyFrom() until no soft error occurs */
                        continue;
                }