diff options
Diffstat (limited to 'src/include/access/nbtxlog.h')
| -rw-r--r-- | src/include/access/nbtxlog.h | 35 |
1 files changed, 19 insertions, 16 deletions
diff --git a/src/include/access/nbtxlog.h b/src/include/access/nbtxlog.h index a605851c981..6320a0098ff 100644 --- 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_HIGHKEY 0x50 /* as above, include truncated highkey */ -#define XLOG_BTREE_SPLIT_R_HIGHKEY 0x60 /* as above, include truncated highkey */ +/* 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 */ @@ -47,6 +46,7 @@ */ typedef struct xl_btree_metadata { + uint32 version; BlockNumber root; uint32 level; BlockNumber fastroot; @@ -80,27 +80,30 @@ typedef struct xl_btree_insert * whole page image. The left page, however, is handled in the normal * incremental-update fashion. * - * Note: the four XLOG_BTREE_SPLIT xl_info codes all use this data record. - * The _L and _R variants indicate whether the inserted tuple went into the - * left or right split page (and thus, whether newitemoff and the new item - * are stored or not). The _HIGHKEY variants indicate that we've logged - * explicitly left page high key value, otherwise redo should use right page - * leftmost key as a left page high key. _HIGHKEY is specified for internal - * pages where right page leftmost key is suppressed, and for leaf pages - * of covering indexes where high key have non-key attributes truncated. + * Note: XLOG_BTREE_SPLIT_L and XLOG_BTREE_SPLIT_R share this data record. + * There are two variants to indicate whether the inserted tuple went into the + * left or right split page (and thus, whether newitemoff and the new item are + * stored or not). We always log the left page high key because suffix + * truncation can generate a new leaf high key using user-defined code. This + * is also necessary on internal pages, since the first right item that the + * left page's high key was based on will have been truncated to zero + * attributes in the right page (the original is unavailable from the right + * page). * * Backup Blk 0: original page / new left page * * The left page's data portion contains the new item, if it's the _L variant. - * (In the _R variants, the new item is one of the right page's tuples.) - * If level > 0, an IndexTuple representing the HIKEY of the left page - * follows. We don't need this on leaf pages, because it's the same as the - * leftmost key in the new right page. + * An IndexTuple representing the high key of the left page must follow with + * either variant. * * Backup Blk 1: new right page * - * The right page's data portion contains the right page's tuples in the - * form used by _bt_restore_page. + * The right page's data portion contains the right page's tuples in the form + * used by _bt_restore_page. This includes the new item, if it's the _R + * variant. The right page's tuples also include the right page's high key + * with either variant (moved from the left/original page during the split), + * unless the split happened to be of the rightmost page on its level, where + * there is no high key for new right page. * * Backup Blk 2: next block (orig page's rightlink), if any * Backup Blk 3: child's left sibling, if non-leaf split |