nbtxlog.h File Reference

#include "access/transam.h"
#include "access/xlogreader.h"
#include "lib/stringinfo.h"
#include "storage/off.h"

Include dependency graph for nbtxlog.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	xl_btree_metadata
struct	xl_btree_insert
struct	xl_btree_split
struct	xl_btree_dedup
struct	xl_btree_reuse_page
struct	xl_btree_vacuum
struct	xl_btree_delete
struct	xl_btree_update
struct	xl_btree_mark_page_halfdead
struct	xl_btree_unlink_page
struct	xl_btree_newroot

Macros
#define	XLOG_BTREE_INSERT_LEAF   0x00 /* add index tuple without split */
#define	XLOG_BTREE_INSERT_UPPER   0x10 /* same, on a non-leaf page */
#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_INSERT_POST   0x50 /* add index tuple with posting split */
#define	XLOG_BTREE_DEDUP   0x60 /* deduplicate tuples for a page */
#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 */
#define	XLOG_BTREE_NEWROOT   0xA0 /* new root page */
#define	XLOG_BTREE_MARK_PAGE_HALFDEAD   0xB0 /* mark a leaf as half-dead */
#define	XLOG_BTREE_VACUUM
#define	XLOG_BTREE_REUSE_PAGE
#define	XLOG_BTREE_META_CLEANUP
#define	SizeOfBtreeInsert   (offsetof(xl_btree_insert, offnum) + sizeof(OffsetNumber))
#define	SizeOfBtreeSplit   (offsetof(xl_btree_split, postingoff) + sizeof(uint16))
#define	SizeOfBtreeDedup   (offsetof(xl_btree_dedup, nintervals) + sizeof(uint16))
#define	SizeOfBtreeReusePage   (offsetof(xl_btree_reuse_page, isCatalogRel) + sizeof(bool))
#define	SizeOfBtreeVacuum   (offsetof(xl_btree_vacuum, nupdated) + sizeof(uint16))
#define	SizeOfBtreeDelete   (offsetof(xl_btree_delete, isCatalogRel) + sizeof(bool))
#define	SizeOfBtreeUpdate   (offsetof(xl_btree_update, ndeletedtids) + sizeof(uint16))
#define	SizeOfBtreeMarkPageHalfDead   (offsetof(xl_btree_mark_page_halfdead, topparent) + sizeof(BlockNumber))
#define	SizeOfBtreeUnlinkPage   (offsetof(xl_btree_unlink_page, leaftopparent) + sizeof(BlockNumber))
#define	SizeOfBtreeNewroot   (offsetof(xl_btree_newroot, level) + sizeof(uint32))

Typedefs
typedef struct xl_btree_metadata	xl_btree_metadata
typedef struct xl_btree_insert	xl_btree_insert
typedef struct xl_btree_split	xl_btree_split
typedef struct xl_btree_dedup	xl_btree_dedup
typedef struct xl_btree_reuse_page	xl_btree_reuse_page
typedef struct xl_btree_vacuum	xl_btree_vacuum
typedef struct xl_btree_delete	xl_btree_delete
typedef struct xl_btree_update	xl_btree_update
typedef struct xl_btree_mark_page_halfdead	xl_btree_mark_page_halfdead
typedef struct xl_btree_unlink_page	xl_btree_unlink_page
typedef struct xl_btree_newroot	xl_btree_newroot

Functions
void	btree_redo (XLogReaderState *record)
void	btree_xlog_startup (void)
void	btree_xlog_cleanup (void)
void	btree_mask (char *pagedata, BlockNumber blkno)
void	btree_desc (StringInfo buf, XLogReaderState *record)
const char *	btree_identify (uint8 info)

Macro Definition Documentation

SizeOfBtreeDedup

#define SizeOfBtreeDedup   (offsetof(xl_btree_dedup, nintervals) + sizeof(uint16))

Definition at line 174 of file nbtxlog.h.

SizeOfBtreeDelete

#define SizeOfBtreeDelete   (offsetof(xl_btree_delete, isCatalogRel) + sizeof(bool))

Definition at line 253 of file nbtxlog.h.

SizeOfBtreeInsert

#define SizeOfBtreeInsert   (offsetof(xl_btree_insert, offnum) + sizeof(OffsetNumber))

Definition at line 84 of file nbtxlog.h.

SizeOfBtreeMarkPageHalfDead

#define SizeOfBtreeMarkPageHalfDead   (offsetof(xl_btree_mark_page_halfdead, topparent) + sizeof(BlockNumber))

Definition at line 291 of file nbtxlog.h.

SizeOfBtreeNewroot

#define SizeOfBtreeNewroot   (offsetof(xl_btree_newroot, level) + sizeof(uint32))

Definition at line 347 of file nbtxlog.h.

SizeOfBtreeReusePage

#define SizeOfBtreeReusePage   (offsetof(xl_btree_reuse_page, isCatalogRel) + sizeof(bool))

Definition at line 192 of file nbtxlog.h.

SizeOfBtreeSplit

#define SizeOfBtreeSplit   (offsetof(xl_btree_split, postingoff) + sizeof(uint16))

Definition at line 158 of file nbtxlog.h.

SizeOfBtreeUnlinkPage

#define SizeOfBtreeUnlinkPage   (offsetof(xl_btree_unlink_page, leaftopparent) + sizeof(BlockNumber))

Definition at line 328 of file nbtxlog.h.

SizeOfBtreeUpdate

#define SizeOfBtreeUpdate   (offsetof(xl_btree_update, ndeletedtids) + sizeof(uint16))

Definition at line 268 of file nbtxlog.h.

SizeOfBtreeVacuum

#define SizeOfBtreeVacuum   (offsetof(xl_btree_vacuum, nupdated) + sizeof(uint16))

Definition at line 234 of file nbtxlog.h.

XLOG_BTREE_DEDUP

#define XLOG_BTREE_DEDUP   0x60 /* deduplicate tuples for a page */

Definition at line 33 of file nbtxlog.h.

XLOG_BTREE_DELETE

#define XLOG_BTREE_DELETE   0x70 /* delete leaf index tuples for a page */

Definition at line 34 of file nbtxlog.h.

XLOG_BTREE_INSERT_LEAF

#define XLOG_BTREE_INSERT_LEAF   0x00 /* add index tuple without split */

Definition at line 27 of file nbtxlog.h.

XLOG_BTREE_INSERT_META

#define XLOG_BTREE_INSERT_META   0x20 /* same, plus update metapage */

Definition at line 29 of file nbtxlog.h.

XLOG_BTREE_INSERT_POST

#define XLOG_BTREE_INSERT_POST   0x50 /* add index tuple with posting split */

Definition at line 32 of file nbtxlog.h.

XLOG_BTREE_INSERT_UPPER

#define XLOG_BTREE_INSERT_UPPER   0x10 /* same, on a non-leaf page */

Definition at line 28 of file nbtxlog.h.

XLOG_BTREE_MARK_PAGE_HALFDEAD

#define XLOG_BTREE_MARK_PAGE_HALFDEAD   0xB0 /* mark a leaf as half-dead */

Definition at line 38 of file nbtxlog.h.

XLOG_BTREE_META_CLEANUP

#define XLOG_BTREE_META_CLEANUP

Value:

                                         0xE0   /* update cleanup-related data in the
                                         * metapage */

Definition at line 41 of file nbtxlog.h.

XLOG_BTREE_NEWROOT

#define XLOG_BTREE_NEWROOT   0xA0 /* new root page */

Definition at line 37 of file nbtxlog.h.

XLOG_BTREE_REUSE_PAGE

#define XLOG_BTREE_REUSE_PAGE

Value:

                                         0xD0   /* old page is about to be reused from
                                         * FSM */

Definition at line 40 of file nbtxlog.h.

XLOG_BTREE_SPLIT_L

#define XLOG_BTREE_SPLIT_L   0x30 /* add index tuple with split */

Definition at line 30 of file nbtxlog.h.

XLOG_BTREE_SPLIT_R

#define XLOG_BTREE_SPLIT_R   0x40 /* as above, new item on right */

Definition at line 31 of file nbtxlog.h.

XLOG_BTREE_UNLINK_PAGE

#define XLOG_BTREE_UNLINK_PAGE   0x80 /* delete a half-dead page */

Definition at line 35 of file nbtxlog.h.

XLOG_BTREE_UNLINK_PAGE_META

#define XLOG_BTREE_UNLINK_PAGE_META   0x90 /* same, and update metapage */

Definition at line 36 of file nbtxlog.h.

XLOG_BTREE_VACUUM

#define XLOG_BTREE_VACUUM

Value:

                                         0xC0   /* delete entries on a page during
                                         * vacuum */

Definition at line 39 of file nbtxlog.h.

Typedef Documentation

xl_btree_dedup

typedef struct xl_btree_dedup xl_btree_dedup

xl_btree_delete

typedef struct xl_btree_delete xl_btree_delete

xl_btree_insert

typedef struct xl_btree_insert xl_btree_insert

xl_btree_mark_page_halfdead

typedef struct xl_btree_mark_page_halfdead xl_btree_mark_page_halfdead

xl_btree_metadata

typedef struct xl_btree_metadata xl_btree_metadata

xl_btree_newroot

typedef struct xl_btree_newroot xl_btree_newroot

xl_btree_reuse_page

typedef struct xl_btree_reuse_page xl_btree_reuse_page

xl_btree_split

typedef struct xl_btree_split xl_btree_split

xl_btree_unlink_page

typedef struct xl_btree_unlink_page xl_btree_unlink_page

xl_btree_update

typedef struct xl_btree_update xl_btree_update

xl_btree_vacuum

typedef struct xl_btree_vacuum xl_btree_vacuum

Function Documentation

btree_desc()

void btree_desc	(	StringInfo	buf,
		XLogReaderState *	record
	)

Definition at line 24 of file nbtdesc.c.

{
    char       *rec = XLogRecGetData(record);
    uint8       info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
 
    switch (info)
    {
        case XLOG_BTREE_INSERT_LEAF:
        case XLOG_BTREE_INSERT_UPPER:
        case XLOG_BTREE_INSERT_META:
        case XLOG_BTREE_INSERT_POST:
            {
                xl_btree_insert *xlrec = (xl_btree_insert *) rec;
 
                appendStringInfo(buf, "off: %u", xlrec->offnum);
                break;
            }
        case XLOG_BTREE_SPLIT_L:
        case XLOG_BTREE_SPLIT_R:
            {
                xl_btree_split *xlrec = (xl_btree_split *) rec;
 
                appendStringInfo(buf, "level: %u, firstrightoff: %d, newitemoff: %d, postingoff: %d",
                                 xlrec->level, xlrec->firstrightoff,
                                 xlrec->newitemoff, xlrec->postingoff);
                break;
            }
        case XLOG_BTREE_DEDUP:
            {
                xl_btree_dedup *xlrec = (xl_btree_dedup *) rec;
 
                appendStringInfo(buf, "nintervals: %u", xlrec->nintervals);
                break;
            }
        case XLOG_BTREE_VACUUM:
            {
                xl_btree_vacuum *xlrec = (xl_btree_vacuum *) rec;
 
                appendStringInfo(buf, "ndeleted: %u, nupdated: %u",
                                 xlrec->ndeleted, xlrec->nupdated);
 
                if (XLogRecHasBlockData(record, 0))
                    delvacuum_desc(buf, XLogRecGetBlockData(record, 0, NULL),
                                   xlrec->ndeleted, xlrec->nupdated);
                break;
            }
        case XLOG_BTREE_DELETE:
            {
                xl_btree_delete *xlrec = (xl_btree_delete *) rec;
 
                appendStringInfo(buf, "snapshotConflictHorizon: %u, ndeleted: %u, nupdated: %u, isCatalogRel: %c",
                                 xlrec->snapshotConflictHorizon,
                                 xlrec->ndeleted, xlrec->nupdated,
                                 xlrec->isCatalogRel ? 'T' : 'F');
 
                if (XLogRecHasBlockData(record, 0))
                    delvacuum_desc(buf, XLogRecGetBlockData(record, 0, NULL),
                                   xlrec->ndeleted, xlrec->nupdated);
                break;
            }
        case XLOG_BTREE_MARK_PAGE_HALFDEAD:
            {
                xl_btree_mark_page_halfdead *xlrec = (xl_btree_mark_page_halfdead *) rec;
 
                appendStringInfo(buf, "topparent: %u, leaf: %u, left: %u, right: %u",
                                 xlrec->topparent, xlrec->leafblk, xlrec->leftblk, xlrec->rightblk);
                break;
            }
        case XLOG_BTREE_UNLINK_PAGE_META:
        case XLOG_BTREE_UNLINK_PAGE:
            {
                xl_btree_unlink_page *xlrec = (xl_btree_unlink_page *) rec;
 
                appendStringInfo(buf, "left: %u, right: %u, level: %u, safexid: %u:%u, ",
                                 xlrec->leftsib, xlrec->rightsib, xlrec->level,
                                 EpochFromFullTransactionId(xlrec->safexid),
                                 XidFromFullTransactionId(xlrec->safexid));
                appendStringInfo(buf, "leafleft: %u, leafright: %u, leaftopparent: %u",
                                 xlrec->leafleftsib, xlrec->leafrightsib,
                                 xlrec->leaftopparent);
                break;
            }
        case XLOG_BTREE_NEWROOT:
            {
                xl_btree_newroot *xlrec = (xl_btree_newroot *) rec;
 
                appendStringInfo(buf, "level: %u", xlrec->level);
                break;
            }
        case XLOG_BTREE_REUSE_PAGE:
            {
                xl_btree_reuse_page *xlrec = (xl_btree_reuse_page *) rec;
 
                appendStringInfo(buf, "rel: %u/%u/%u, snapshotConflictHorizon: %u:%u, isCatalogRel: %c",
                                 xlrec->locator.spcOid, xlrec->locator.dbOid,
                                 xlrec->locator.relNumber,
                                 EpochFromFullTransactionId(xlrec->snapshotConflictHorizon),
                                 XidFromFullTransactionId(xlrec->snapshotConflictHorizon),
                                 xlrec->isCatalogRel ? 'T' : 'F');
                break;
            }
        case XLOG_BTREE_META_CLEANUP:
            {
                xl_btree_metadata *xlrec;
 
                xlrec = (xl_btree_metadata *) XLogRecGetBlockData(record, 0,
                                                                  NULL);
                appendStringInfo(buf, "last_cleanup_num_delpages: %u",
                                 xlrec->last_cleanup_num_delpages);
                break;
            }
    }
}

References appendStringInfo(), buf, RelFileLocator::dbOid, delvacuum_desc(), EpochFromFullTransactionId, xl_btree_split::firstrightoff, xl_btree_reuse_page::isCatalogRel, xl_btree_delete::isCatalogRel, xl_btree_metadata::last_cleanup_num_delpages, xl_btree_mark_page_halfdead::leafblk, xl_btree_unlink_page::leafleftsib, xl_btree_unlink_page::leafrightsib, xl_btree_unlink_page::leaftopparent, xl_btree_mark_page_halfdead::leftblk, xl_btree_unlink_page::leftsib, xl_btree_split::level, xl_btree_unlink_page::level, xl_btree_newroot::level, xl_btree_reuse_page::locator, xl_btree_vacuum::ndeleted, xl_btree_delete::ndeleted, xl_btree_split::newitemoff, xl_btree_dedup::nintervals, xl_btree_vacuum::nupdated, xl_btree_delete::nupdated, xl_btree_insert::offnum, xl_btree_split::postingoff, RelFileLocator::relNumber, xl_btree_mark_page_halfdead::rightblk, xl_btree_unlink_page::rightsib, xl_btree_unlink_page::safexid, xl_btree_reuse_page::snapshotConflictHorizon, xl_btree_delete::snapshotConflictHorizon, RelFileLocator::spcOid, xl_btree_mark_page_halfdead::topparent, XidFromFullTransactionId, XLOG_BTREE_DEDUP, XLOG_BTREE_DELETE, XLOG_BTREE_INSERT_LEAF, XLOG_BTREE_INSERT_META, XLOG_BTREE_INSERT_POST, XLOG_BTREE_INSERT_UPPER, XLOG_BTREE_MARK_PAGE_HALFDEAD, XLOG_BTREE_META_CLEANUP, XLOG_BTREE_NEWROOT, XLOG_BTREE_REUSE_PAGE, XLOG_BTREE_SPLIT_L, XLOG_BTREE_SPLIT_R, XLOG_BTREE_UNLINK_PAGE, XLOG_BTREE_UNLINK_PAGE_META, XLOG_BTREE_VACUUM, XLogRecGetBlockData(), XLogRecGetData, XLogRecGetInfo, and XLogRecHasBlockData.

btree_identify()

const char * btree_identify

(

uint8

info

)

Definition at line 139 of file nbtdesc.c.

{
    const char *id = NULL;
 
    switch (info & ~XLR_INFO_MASK)
    {
        case XLOG_BTREE_INSERT_LEAF:
            id = "INSERT_LEAF";
            break;
        case XLOG_BTREE_INSERT_UPPER:
            id = "INSERT_UPPER";
            break;
        case XLOG_BTREE_INSERT_META:
            id = "INSERT_META";
            break;
        case XLOG_BTREE_SPLIT_L:
            id = "SPLIT_L";
            break;
        case XLOG_BTREE_SPLIT_R:
            id = "SPLIT_R";
            break;
        case XLOG_BTREE_INSERT_POST:
            id = "INSERT_POST";
            break;
        case XLOG_BTREE_DEDUP:
            id = "DEDUP";
            break;
        case XLOG_BTREE_VACUUM:
            id = "VACUUM";
            break;
        case XLOG_BTREE_DELETE:
            id = "DELETE";
            break;
        case XLOG_BTREE_MARK_PAGE_HALFDEAD:
            id = "MARK_PAGE_HALFDEAD";
            break;
        case XLOG_BTREE_UNLINK_PAGE:
            id = "UNLINK_PAGE";
            break;
        case XLOG_BTREE_UNLINK_PAGE_META:
            id = "UNLINK_PAGE_META";
            break;
        case XLOG_BTREE_NEWROOT:
            id = "NEWROOT";
            break;
        case XLOG_BTREE_REUSE_PAGE:
            id = "REUSE_PAGE";
            break;
        case XLOG_BTREE_META_CLEANUP:
            id = "META_CLEANUP";
            break;
    }
 
    return id;
}

References XLOG_BTREE_DEDUP, XLOG_BTREE_DELETE, XLOG_BTREE_INSERT_LEAF, XLOG_BTREE_INSERT_META, XLOG_BTREE_INSERT_POST, XLOG_BTREE_INSERT_UPPER, XLOG_BTREE_MARK_PAGE_HALFDEAD, XLOG_BTREE_META_CLEANUP, XLOG_BTREE_NEWROOT, XLOG_BTREE_REUSE_PAGE, XLOG_BTREE_SPLIT_L, XLOG_BTREE_SPLIT_R, XLOG_BTREE_UNLINK_PAGE, XLOG_BTREE_UNLINK_PAGE_META, XLOG_BTREE_VACUUM, and XLR_INFO_MASK.

btree_mask()

void btree_mask	(	char *	pagedata,
		BlockNumber	blkno
	)

Definition at line 1081 of file nbtxlog.c.

{
    Page        page = (Page) pagedata;
    BTPageOpaque maskopaq;
 
    mask_page_lsn_and_checksum(page);
 
    mask_page_hint_bits(page);
    mask_unused_space(page);
 
    maskopaq = BTPageGetOpaque(page);
 
    if (P_ISLEAF(maskopaq))
    {
        /*
         * In btree leaf pages, it is possible to modify the LP_FLAGS without
         * emitting any WAL record. Hence, mask the line pointer flags. See
         * _bt_killitems(), _bt_check_unique() for details.
         */
        mask_lp_flags(page);
    }
 
    /*
     * BTP_HAS_GARBAGE is just an un-logged hint bit. So, mask it. See
     * _bt_delete_or_dedup_one_page(), _bt_killitems(), and _bt_check_unique()
     * for details.
     */
    maskopaq->btpo_flags &= ~BTP_HAS_GARBAGE;
 
    /*
     * During replay of a btree page split, we don't set the BTP_SPLIT_END
     * flag of the right sibling and initialize the cycle_id to 0 for the same
     * page. See btree_xlog_split() for details.
     */
    maskopaq->btpo_flags &= ~BTP_SPLIT_END;
    maskopaq->btpo_cycleid = 0;
}

References BTPageGetOpaque, BTPageOpaqueData::btpo_cycleid, BTPageOpaqueData::btpo_flags, mask_lp_flags(), mask_page_hint_bits(), mask_page_lsn_and_checksum(), mask_unused_space(), and P_ISLEAF.

btree_redo()

void btree_redo

(

XLogReaderState *

record

)

Definition at line 1004 of file nbtxlog.c.

{
    uint8       info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
    MemoryContext oldCtx;
 
    oldCtx = MemoryContextSwitchTo(opCtx);
    switch (info)
    {
        case XLOG_BTREE_INSERT_LEAF:
            btree_xlog_insert(true, false, false, record);
            break;
        case XLOG_BTREE_INSERT_UPPER:
            btree_xlog_insert(false, false, false, record);
            break;
        case XLOG_BTREE_INSERT_META:
            btree_xlog_insert(false, true, false, record);
            break;
        case XLOG_BTREE_SPLIT_L:
            btree_xlog_split(true, record);
            break;
        case XLOG_BTREE_SPLIT_R:
            btree_xlog_split(false, record);
            break;
        case XLOG_BTREE_INSERT_POST:
            btree_xlog_insert(true, false, true, record);
            break;
        case XLOG_BTREE_DEDUP:
            btree_xlog_dedup(record);
            break;
        case XLOG_BTREE_VACUUM:
            btree_xlog_vacuum(record);
            break;
        case XLOG_BTREE_DELETE:
            btree_xlog_delete(record);
            break;
        case XLOG_BTREE_MARK_PAGE_HALFDEAD:
            btree_xlog_mark_page_halfdead(info, record);
            break;
        case XLOG_BTREE_UNLINK_PAGE:
        case XLOG_BTREE_UNLINK_PAGE_META:
            btree_xlog_unlink_page(info, record);
            break;
        case XLOG_BTREE_NEWROOT:
            btree_xlog_newroot(record);
            break;
        case XLOG_BTREE_REUSE_PAGE:
            btree_xlog_reuse_page(record);
            break;
        case XLOG_BTREE_META_CLEANUP:
            _bt_restore_meta(record, 0);
            break;
        default:
            elog(PANIC, "btree_redo: unknown op code %u", info);
    }
    MemoryContextSwitchTo(oldCtx);
    MemoryContextReset(opCtx);
}

References _bt_restore_meta(), btree_xlog_dedup(), btree_xlog_delete(), btree_xlog_insert(), btree_xlog_mark_page_halfdead(), btree_xlog_newroot(), btree_xlog_reuse_page(), btree_xlog_split(), btree_xlog_unlink_page(), btree_xlog_vacuum(), elog, MemoryContextReset(), MemoryContextSwitchTo(), opCtx, PANIC, XLOG_BTREE_DEDUP, XLOG_BTREE_DELETE, XLOG_BTREE_INSERT_LEAF, XLOG_BTREE_INSERT_META, XLOG_BTREE_INSERT_POST, XLOG_BTREE_INSERT_UPPER, XLOG_BTREE_MARK_PAGE_HALFDEAD, XLOG_BTREE_META_CLEANUP, XLOG_BTREE_NEWROOT, XLOG_BTREE_REUSE_PAGE, XLOG_BTREE_SPLIT_L, XLOG_BTREE_SPLIT_R, XLOG_BTREE_UNLINK_PAGE, XLOG_BTREE_UNLINK_PAGE_META, XLOG_BTREE_VACUUM, and XLogRecGetInfo.

btree_xlog_cleanup()

void btree_xlog_cleanup

(

void

)

Definition at line 1071 of file nbtxlog.c.

{
    MemoryContextDelete(opCtx);
    opCtx = NULL;
}

References MemoryContextDelete(), and opCtx.

btree_xlog_startup()

void btree_xlog_startup

(

void

)

Definition at line 1063 of file nbtxlog.c.

{
    opCtx = AllocSetContextCreate(CurrentMemoryContext,
                                  "Btree recovery temporary context",
                                  ALLOCSET_DEFAULT_SIZES);
}

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, CurrentMemoryContext, and opCtx.