Remove dedicated B-tree root-split record types.

Since commit 40dae7ec53, which changed the way b-tree page splitting
works, there has been no difference in the handling of root, and non-root
split WAL records. We don't need to distinguish them anymore

If you're worried about the loss of debugging information, note that
usually a root split record will normally be followed by a WAL record to
create the new root page. The root page will also have the BTP_ROOT flag
set on the page itself, and there is a pointer to it from the metapage.

Author: Aleksander Alekseev
Discussion: https://www.postgresql.org/message-id/20170406122116.GA11081@e733.localdomain

diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c
index 4aca7e4db8f8cef3b7e3dede0d456f50f42084f5..bf963fcdef22252f79b10ae6f1280ce42ef630a5 100644 (file)
--- a/src/backend/access/nbtree/nbtinsert.c
+++ b/src/backend/access/nbtree/nbtinsert.c
@@ -980,7 +980,6 @@ _bt_split(Relation rel, Buffer buf, Buffer cbuf, OffsetNumber firstright,
                rightoff;
    OffsetNumber maxoff;
    OffsetNumber i;
-   bool        isroot;
    bool        isleaf;
 
    /* Acquire a new page to split into */
@@ -1019,7 +1018,6 @@ _bt_split(Relation rel, Buffer buf, Buffer cbuf, OffsetNumber firstright,
    lopaque = (BTPageOpaque) PageGetSpecialPointer(leftpage);
    ropaque = (BTPageOpaque) PageGetSpecialPointer(rightpage);
 
-   isroot = P_ISROOT(oopaque);
    isleaf = P_ISLEAF(oopaque);
 
    /* if we're splitting this page, it won't be the root when we're done */
@@ -1330,11 +1328,7 @@ _bt_split(Relation rel, Buffer buf, Buffer cbuf, OffsetNumber firstright,
                            (char *) rightpage + ((PageHeader) rightpage)->pd_upper,
                            ((PageHeader) rightpage)->pd_special - ((PageHeader) rightpage)->pd_upper);
 
-       if (isroot)
-           xlinfo = newitemonleft ? XLOG_BTREE_SPLIT_L_ROOT : XLOG_BTREE_SPLIT_R_ROOT;
-       else
-           xlinfo = newitemonleft ? XLOG_BTREE_SPLIT_L : XLOG_BTREE_SPLIT_R;
-
+       xlinfo = newitemonleft ? XLOG_BTREE_SPLIT_L : XLOG_BTREE_SPLIT_R;
        recptr = XLogInsert(RM_BTREE_ID, xlinfo);
 
        PageSetLSN(origpage, recptr);

diff --git a/src/backend/access/nbtree/nbtxlog.c b/src/backend/access/nbtree/nbtxlog.c
index ac60db0d4904b4525a928948645c6f175fef169f..3610c7c7e0f5521fe4df95cb304ce5ff7cedf7cd 100644 (file)
--- a/src/backend/access/nbtree/nbtxlog.c
+++ b/src/backend/access/nbtree/nbtxlog.c
@@ -193,7 +193,7 @@ btree_xlog_insert(bool isleaf, bool ismeta, XLogReaderState *record)
 }
 
 static void
-btree_xlog_split(bool onleft, bool isroot, XLogReaderState *record)
+btree_xlog_split(bool onleft, XLogReaderState *record)
 {
    XLogRecPtr  lsn = record->EndRecPtr;
    xl_btree_split *xlrec = (xl_btree_split *) XLogRecGetData(record);
@@ -996,16 +996,10 @@ btree_redo(XLogReaderState *record)
            btree_xlog_insert(false, true, record);
            break;
        case XLOG_BTREE_SPLIT_L:
-           btree_xlog_split(true, false, record);
+           btree_xlog_split(true, record);
            break;
        case XLOG_BTREE_SPLIT_R:
-           btree_xlog_split(false, false, record);
-           break;
-       case XLOG_BTREE_SPLIT_L_ROOT:
-           btree_xlog_split(true, true, record);
-           break;
-       case XLOG_BTREE_SPLIT_R_ROOT:
-           btree_xlog_split(false, true, record);
+           btree_xlog_split(false, record);
            break;
        case XLOG_BTREE_VACUUM:
            btree_xlog_vacuum(record);

diff --git a/src/backend/access/rmgrdesc/nbtdesc.c b/src/backend/access/rmgrdesc/nbtdesc.c
index ad6bba6130bd0d3c1d969961452b0597f5900c5f..a3e1331fe292a6bbf8e34936842f7384c2e772e6 100644 (file)
--- a/src/backend/access/rmgrdesc/nbtdesc.c
+++ b/src/backend/access/rmgrdesc/nbtdesc.c
@@ -35,8 +35,6 @@ btree_desc(StringInfo buf, XLogReaderState *record)
            }
        case XLOG_BTREE_SPLIT_L:
        case XLOG_BTREE_SPLIT_R:
-       case XLOG_BTREE_SPLIT_L_ROOT:
-       case XLOG_BTREE_SPLIT_R_ROOT:
            {
                xl_btree_split *xlrec = (xl_btree_split *) rec;
 
@@ -121,12 +119,6 @@ btree_identify(uint8 info)
        case XLOG_BTREE_SPLIT_R:
            id = "SPLIT_R";
            break;
-       case XLOG_BTREE_SPLIT_L_ROOT:
-           id = "SPLIT_L_ROOT";
-           break;
-       case XLOG_BTREE_SPLIT_R_ROOT:
-           id = "SPLIT_R_ROOT";
-           break;
        case XLOG_BTREE_VACUUM:
            id = "VACUUM";
            break;

diff --git a/src/include/access/nbtxlog.h b/src/include/access/nbtxlog.h
index a46e9c36f33537c1ec7eabea43df0fdc888843f2..e3cddb2e641892fd3a39b36a1ba227bf9967e39e 100644 (file)
--- a/src/include/access/nbtxlog.h
+++ b/src/include/access/nbtxlog.h
@@ -28,8 +28,7 @@
 #define XLOG_BTREE_INSERT_META 0x20    /* same, plus update metapage */
 #define XLOG_BTREE_SPLIT_L     0x30    /* add index tuple with split */
 #define XLOG_BTREE_SPLIT_R     0x40    /* as above, new item on right */
-#define XLOG_BTREE_SPLIT_L_ROOT 0x50   /* add tuple with split of root */
-#define XLOG_BTREE_SPLIT_R_ROOT 0x60   /* as above, new item on right */
+/* 0x50 and 0x60 are unused */
 #define XLOG_BTREE_DELETE      0x70    /* delete leaf index tuples for a page */
 #define XLOG_BTREE_UNLINK_PAGE 0x80    /* delete a half-dead page */
 #define XLOG_BTREE_UNLINK_PAGE_META 0x90   /* same, and update metapage */