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Fix dropping of relational/non-relational data from storage

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This commit is contained in:
Konstantin Knizhnik
2021-05-25 15:13:14 +03:00
parent 2b7963056c
commit 3865a8d901
6 changed files with 190 additions and 102 deletions
Download Patch File Download Diff File Expand all files Collapse all files
pageserver/src/repository.rs
+38 -27
View File
@@ -63,14 +63,17 @@ pub trait Timeline {
///
/// This will implicitly extend the relation, if the page is beyond the
/// current end-of-file.
fn put_wal_record(&self, tag: BufferTag, rec: WALRecord);
fn put_wal_record(&self, tag: BufferTag, rec: WALRecord) -> Result<()>;
/// Like put_wal_record, but with ready-made image of the page.
fn put_page_image(&self, tag: BufferTag, lsn: Lsn, img: Bytes);
fn put_page_image(&self, tag: BufferTag, lsn: Lsn, img: Bytes) -> Result<()>;
/// Truncate relation
fn put_truncation(&self, rel: RelTag, lsn: Lsn, nblocks: u32) -> Result<()>;
/// Drop relation or file segment
fn put_drop(&self, tag: BufferTag, lsn: Lsn) -> Result<()>;
/// Put raw data
fn put_raw_data(&self, key: RepositoryKey, data: &[u8]) -> Result<()>;
@@ -156,14 +159,18 @@ pub trait Timeline {
blknum: blk.blkno,
};
let rec = WALRecord {
lsn,
will_init: blk.will_init || blk.apply_image,
rec: recdata.clone(),
main_data_offset: decoded.main_data_offset as u32,
};
if blk.will_drop {
self.put_drop(tag, lsn)?;
} else {
let rec = WALRecord {
lsn,
will_init: blk.will_init || blk.apply_image,
rec: recdata.clone(),
main_data_offset: decoded.main_data_offset as u32,
};
self.put_wal_record(tag, rec);
self.put_wal_record(tag, rec)?;
}
}
// Handle a few special record types
@@ -285,6 +292,21 @@ pub trait Timeline {
return Ok(dbs);
}
fn get_tx_status(&self, xid: TransactionId, lsn: Lsn) -> Result<u8> {
let tag = BufferTag {
rel: RelTag {
forknum: pg_constants::PG_XACT_FORKNUM,
spcnode: 0,
dbnode: 0,
relnode: 0,
},
blknum: xid / pg_constants::CLOG_XACTS_PER_PAGE,
};
let clog_page = self.get_page_at_lsn(tag, lsn)?;
let status = transaction_id_get_status(xid, &clog_page[..]);
Ok(status)
}
/// Get vector of prepared twophase transactions
fn get_twophase(&self, lsn: Lsn) -> Result<Vec<TransactionId>> {
let key = RepositoryKey {
@@ -311,18 +333,7 @@ pub trait Timeline {
}
if key.lsn <= lsn {
let xid = key.tag.blknum;
let tag = BufferTag {
rel: RelTag {
forknum: pg_constants::PG_XACT_FORKNUM,
spcnode: 0,
dbnode: 0,
relnode: 0,
},
blknum: xid / pg_constants::CLOG_XACTS_PER_PAGE,
};
let clog_page = self.get_page_at_lsn(tag, lsn)?;
let status = transaction_id_get_status(xid, &clog_page[..]);
if status == pg_constants::TRANSACTION_STATUS_IN_PROGRESS {
if self.get_tx_status(xid, lsn)? == pg_constants::TRANSACTION_STATUS_IN_PROGRESS {
gxacts.push(xid);
}
}
@@ -567,11 +578,11 @@ mod tests {
let tline = repo.create_empty_timeline(timelineid)?;
tline.init_valid_lsn(Lsn(1));
tline.put_page_image(TEST_BUF(0), Lsn(2), TEST_IMG("foo blk 0 at 2"));
tline.put_page_image(TEST_BUF(0), Lsn(2), TEST_IMG("foo blk 0 at 2"));
tline.put_page_image(TEST_BUF(0), Lsn(3), TEST_IMG("foo blk 0 at 3"));
tline.put_page_image(TEST_BUF(1), Lsn(4), TEST_IMG("foo blk 1 at 4"));
tline.put_page_image(TEST_BUF(2), Lsn(5), TEST_IMG("foo blk 2 at 5"));
tline.put_page_image(TEST_BUF(0), Lsn(2), TEST_IMG("foo blk 0 at 2"))?;
tline.put_page_image(TEST_BUF(0), Lsn(2), TEST_IMG("foo blk 0 at 2"))?;
tline.put_page_image(TEST_BUF(0), Lsn(3), TEST_IMG("foo blk 0 at 3"))?;
tline.put_page_image(TEST_BUF(1), Lsn(4), TEST_IMG("foo blk 1 at 4"))?;
tline.put_page_image(TEST_BUF(2), Lsn(5), TEST_IMG("foo blk 2 at 5"))?;
tline.advance_last_valid_lsn(Lsn(5));
@@ -661,7 +672,7 @@ mod tests {
for i in 0..pg_constants::RELSEG_SIZE + 1 {
let img = TEST_IMG(&format!("foo blk {} at {}", i, Lsn(lsn)));
lsn += 1;
tline.put_page_image(TEST_BUF(i as u32), Lsn(lsn), img);
tline.put_page_image(TEST_BUF(i as u32), Lsn(lsn), img)?;
}
tline.advance_last_valid_lsn(Lsn(lsn));
pageserver/src/repository/rocksdb.rs
+121 -61
View File
@@ -87,6 +87,7 @@ enum CacheEntryContent {
PageImage(Bytes),
WALRecord(WALRecord),
Truncation,
Drop,
}
// The serialized representation of a CacheEntryContent begins with
@@ -94,11 +95,12 @@ enum CacheEntryContent {
// an UNUSED_VERSION_FLAG that is not represented in the CacheEntryContent
// at all, you must peek into the first byte of the serialized representation
// to read it.
const CONTENT_PAGE_IMAGE: u8 = 1u8;
const CONTENT_WAL_RECORD: u8 = 2u8;
const CONTENT_TRUNCATION: u8 = 3u8;
const CONTENT_PAGE_IMAGE: u8 = 0u8;
const CONTENT_WAL_RECORD: u8 = 1u8;
const CONTENT_TRUNCATION: u8 = 2u8;
const CONTENT_DROP: u8 = 3u8;
const CONTENT_KIND_MASK: u8 = 3u8; // bitmask that covers the above
const CONTENT_KIND_MASK: u8 = 3u8; // bitmask that covers the above
const UNUSED_VERSION_FLAG: u8 = 4u8;
@@ -117,6 +119,9 @@ impl CacheEntryContent {
CacheEntryContent::Truncation => {
buf.put_u8(CONTENT_TRUNCATION);
}
CacheEntryContent::Drop => {
buf.put_u8(CONTENT_DROP);
}
}
}
pub fn unpack(buf: &mut Bytes) -> CacheEntryContent {
@@ -131,6 +136,7 @@ impl CacheEntryContent {
}
CONTENT_WAL_RECORD => CacheEntryContent::WALRecord(WALRecord::unpack(buf)),
CONTENT_TRUNCATION => CacheEntryContent::Truncation,
CONTENT_DROP => CacheEntryContent::Drop,
_ => unreachable!(),
}
}
@@ -299,17 +305,17 @@ impl RocksTimeline {
let mut base_img: Option<Bytes> = None;
let mut records: Vec<WALRecord> = Vec::new();
let mut iter = self.db.raw_iterator();
iter.seek_for_prev(key.to_bytes());
let mut iter = self.iterator();
iter.last(&key);
// Scan backwards, collecting the WAL records, until we hit an
// old page image.
while iter.valid() {
let key = RepositoryKey::from_slice(iter.key().unwrap());
let key = iter.key();
if key.tag != tag {
break;
}
let content = CacheEntryContent::from_slice(iter.value().unwrap());
let content = CacheEntryContent::from_slice(iter.value());
if let CacheEntryContent::PageImage(img) = content {
// We have a base image. No need to dig deeper into the list of
// records
@@ -347,11 +353,11 @@ impl RocksTimeline {
},
lsn,
};
let mut iter = self.db.raw_iterator();
let mut iter = self.iterator();
loop {
iter.seek_for_prev(key.to_bytes());
iter.last(&key);
if iter.valid() {
let thiskey = RepositoryKey::from_slice(iter.key().unwrap());
let thiskey = iter.key();
if thiskey.tag.rel == rel {
// Ignore entries with later LSNs.
if thiskey.lsn > lsn {
@@ -359,7 +365,7 @@ impl RocksTimeline {
continue;
}
let content = CacheEntryContent::from_slice(iter.value().unwrap());
let content = CacheEntryContent::from_slice(iter.value());
if let CacheEntryContent::Truncation = content {
if thiskey.tag.blknum > 0 {
key.tag.blknum = thiskey.tag.blknum - 1;
@@ -378,6 +384,46 @@ impl RocksTimeline {
Ok(0)
}
///
/// Drop relations with all its forks or non-relational file
///
fn drop(&self, tag: BufferTag) -> Result<()> {
let mut iter = self.iterator();
let mut key = RepositoryKey { tag, lsn: Lsn(u64::MAX) };
if tag.rel.forknum == pg_constants::MAIN_FORKNUM {
// if it is relation then remove all its blocks in all forks
key.tag.blknum = u32::MAX;
key.tag.rel.forknum = pg_constants::INIT_FORKNUM;
} else {
assert!(tag.rel.forknum > pg_constants::INIT_FORKNUM);
}
iter.last(&key);
while iter.valid() {
let key = iter.key();
if key.tag.rel.relnode != tag.rel.relnode ||
key.tag.rel.spcnode != tag.rel.spcnode ||
key.tag.rel.dbnode != tag.rel.dbnode ||
(key.tag.rel.forknum != tag.rel.forknum &&
tag.rel.forknum != pg_constants::MAIN_FORKNUM)
{
// no more entries belonging to this relation or file
break;
}
let v = iter.value();
if (v[0] & UNUSED_VERSION_FLAG) == 0 {
let mut v = v.to_owned();
v[0] |= UNUSED_VERSION_FLAG;
self.db.put(key.to_bytes(), &v[..])?;
} else {
// already marked for deletion
break;
}
iter.prev();
}
Ok(())
}
fn do_gc(&self, conf: &'static PageServerConf) -> Result<Bytes> {
loop {
thread::sleep(conf.gc_period);
@@ -403,35 +449,50 @@ impl RocksTimeline {
let mut inspected = 0u64;
let mut deleted = 0u64;
loop {
let mut iter = self.db.raw_iterator();
iter.seek_for_prev(maxkey.to_bytes());
let mut iter = self.iterator();
iter.last(&maxkey);
if iter.valid() {
let key = RepositoryKey::from_slice(iter.key().unwrap());
let v = iter.value().unwrap();
let key = iter.key();
let v = iter.value();
let flag = v[0];
let last_lsn = key.lsn;
inspected += 1;
// Construct boundaries for old records cleanup
maxkey.tag = key.tag;
let last_lsn = key.lsn;
maxkey.lsn = min(horizon, last_lsn); // do not remove last version
let mut minkey = maxkey.clone();
minkey.lsn = Lsn(0); // first version
// Special handling of delete of PREPARE WAL record
if (flag & CONTENT_KIND_MASK) == CONTENT_DROP {
// If drop record in over the horizon then delete all entries from repository
if last_lsn < horizon {
self.drop(key.tag)?;
}
maxkey = minkey;
continue;
}
// Special handling of PREPARE transaction WAL record.
if last_lsn < horizon
&& key.tag.rel.forknum == pg_constants::PG_TWOPHASE_FORKNUM
{
if (v[0] & UNUSED_VERSION_FLAG) == 0 {
let mut v = v.to_owned();
v[0] |= UNUSED_VERSION_FLAG;
self.db.put(key.to_bytes(), &v[..])?;
deleted += 1;
}
maxkey = minkey;
continue;
}
let xid = key.tag.blknum;
// We can not remove information about uncompleted prepared transaction
// even if it is over horizon
if self.get_tx_status(xid, horizon)? != pg_constants::TRANSACTION_STATUS_IN_PROGRESS {
if (v[0] & UNUSED_VERSION_FLAG) == 0 {
let mut v = v.to_owned();
v[0] |= UNUSED_VERSION_FLAG;
self.db.put(key.to_bytes(), &v[..])?;
deleted += 1;
}
}
maxkey = minkey;
continue;
}
// reconstruct most recent page version
if (v[0] & CONTENT_KIND_MASK) == CONTENT_WAL_RECORD {
// force reconstruction of most recent page version
@@ -449,19 +510,19 @@ impl RocksTimeline {
let new_img = self
.walredo_mgr
.request_redo(key.tag, key.lsn, base_img, records)?;
self.put_page_image(key.tag, key.lsn, new_img.clone());
self.put_page_image(key.tag, key.lsn, new_img.clone())?;
reconstructed += 1;
}
iter.seek_for_prev(maxkey.to_bytes());
iter.last(&maxkey);
if iter.valid() {
// do not remove last version
if last_lsn > horizon {
// locate most recent record before horizon
let key = RepositoryKey::from_slice(iter.key().unwrap());
let key = iter.key();
if key.tag == maxkey.tag {
let v = iter.value().unwrap();
let v = iter.value();
if (v[0] & CONTENT_KIND_MASK) == CONTENT_WAL_RECORD {
let (base_img, records) =
self.collect_records_for_apply(key.tag, key.lsn);
@@ -470,7 +531,7 @@ impl RocksTimeline {
let new_img = self
.walredo_mgr
.request_redo(key.tag, key.lsn, base_img, records)?;
self.put_page_image(key.tag, key.lsn, new_img.clone());
self.put_page_image(key.tag, key.lsn, new_img.clone())?;
truncated += 1;
} else {
@@ -497,11 +558,11 @@ impl RocksTimeline {
if !iter.valid() {
break;
}
let key = RepositoryKey::from_slice(iter.key().unwrap());
let key = iter.key();
if key.tag != maxkey.tag {
break;
}
let v = iter.value().unwrap();
let v = iter.value();
if (v[0] & UNUSED_VERSION_FLAG) == 0 {
let mut v = v.to_owned();
v[0] |= UNUSED_VERSION_FLAG;
@@ -547,13 +608,13 @@ impl Timeline for RocksTimeline {
// ask the WAL redo service to reconstruct the page image from the WAL records.
let key = RepositoryKey { tag, lsn };
let mut iter = self.db.raw_iterator();
iter.seek_for_prev(key.to_bytes());
let mut iter = self.iterator();
iter.last(&key);
if iter.valid() {
let key = RepositoryKey::from_slice(iter.key().unwrap());
let key = iter.key();
if key.tag == tag {
let content = CacheEntryContent::from_slice(iter.value().unwrap());
let content = CacheEntryContent::from_slice(iter.value());
let page_img: Bytes;
if let CacheEntryContent::PageImage(img) = content {
page_img = img;
@@ -562,7 +623,7 @@ impl Timeline for RocksTimeline {
let (base_img, records) = self.collect_records_for_apply(tag, lsn);
page_img = self.walredo_mgr.request_redo(tag, lsn, base_img, records)?;
self.put_page_image(tag, lsn, page_img.clone());
self.put_page_image(tag, lsn, page_img.clone())?;
} else {
// No base image, and no WAL record. Huh?
bail!(
@@ -616,10 +677,10 @@ impl Timeline for RocksTimeline {
},
lsn,
};
let mut iter = self.db.raw_iterator();
iter.seek_for_prev(key.to_bytes());
let mut iter = self.iterator();
iter.last(&key);
if iter.valid() {
let key = RepositoryKey::from_slice(iter.key().unwrap());
let key = iter.key();
if key.tag.rel == rel {
debug!("Relation {} exists at {}", rel, lsn);
return Ok(true);
@@ -635,13 +696,13 @@ impl Timeline for RocksTimeline {
///
/// Adds a WAL record to the repository
///
fn put_wal_record(&self, tag: BufferTag, rec: WALRecord) {
fn put_wal_record(&self, tag: BufferTag, rec: WALRecord) -> Result<()> {
let lsn = rec.lsn;
let key = RepositoryKey { tag, lsn };
let content = CacheEntryContent::WALRecord(rec);
let _res = self.db.put(key.to_bytes(), content.to_bytes());
let _res = self.db.put(key.to_bytes(), content.to_bytes())?;
trace!(
"put_wal_record rel {} blk {} at {}",
tag.rel,
@@ -651,8 +712,20 @@ impl Timeline for RocksTimeline {
self.num_entries.fetch_add(1, Ordering::Relaxed);
self.num_wal_records.fetch_add(1, Ordering::Relaxed);
Ok(())
}
///
/// Put drop record which should completely delete relation with all its forks
/// or non-relational file from repository
///
fn put_drop(&self, tag: BufferTag, lsn: Lsn) -> Result<()> {
let key = RepositoryKey { tag, lsn };
let content = CacheEntryContent::Drop;
let _res = self.db.put(key.to_bytes(), content.to_bytes())?;
Ok(())
}
///
/// Adds a relation-wide WAL record (like truncate) to the repository,
/// associating it with all pages started with specified block number
@@ -672,7 +745,7 @@ impl Timeline for RocksTimeline {
lsn,
};
trace!("put_wal_record lsn: {}", key.lsn);
let _res = self.db.put(key.to_bytes(), content.to_bytes());
let _res = self.db.put(key.to_bytes(), content.to_bytes())?;
}
let n = (old_rel_size - nblocks) as u64;
self.num_entries.fetch_add(n, Ordering::Relaxed);
@@ -697,26 +770,12 @@ impl Timeline for RocksTimeline {
///
/// Memorize a full image of a page version
///
fn put_page_image(&self, tag: BufferTag, lsn: Lsn, img: Bytes) {
let img_len = img.len();
fn put_page_image(&self, tag: BufferTag, lsn: Lsn, img: Bytes) -> Result<()> {
let key = RepositoryKey { tag, lsn };
let content = CacheEntryContent::PageImage(img);
let mut val_buf = content.to_bytes();
// Zero size of page image indicates that page can be removed
if img_len == 0 {
if (val_buf[0] & UNUSED_VERSION_FLAG) != 0 {
// records already marked for deletion
return;
} else {
// delete truncated multixact page
val_buf[0] |= UNUSED_VERSION_FLAG;
}
}
trace!("put_wal_record lsn: {}", key.lsn);
let _res = self.db.put(key.to_bytes(), content.to_bytes());
let _res = self.db.put(key.to_bytes(), content.to_bytes())?;
trace!(
"put_page_image rel {} blk {} at {}",
@@ -725,6 +784,7 @@ impl Timeline for RocksTimeline {
lsn
);
self.num_page_images.fetch_add(1, Ordering::Relaxed);
Ok(())
}
fn iterator(&self) -> Box<dyn RepositoryIterator + '_> {
pageserver/src/restore_local_repo.rs
+4 -4
View File
@@ -279,7 +279,7 @@ fn restore_relfile(
},
blknum,
};
timeline.put_page_image(tag, lsn, Bytes::copy_from_slice(&buf));
timeline.put_page_image(tag, lsn, Bytes::copy_from_slice(&buf))?;
/*
if oldest_lsn == 0 || p.lsn < oldest_lsn {
oldest_lsn = p.lsn;
@@ -335,7 +335,7 @@ fn restore_nonrel_file(
},
blknum,
};
timeline.put_page_image(tag, lsn, Bytes::copy_from_slice(&buffer[..]));
timeline.put_page_image(tag, lsn, Bytes::copy_from_slice(&buffer[..]))?;
Ok(())
}
@@ -369,7 +369,7 @@ fn restore_slru_file(
},
blknum,
};
timeline.put_page_image(tag, lsn, Bytes::copy_from_slice(&buf));
timeline.put_page_image(tag, lsn, Bytes::copy_from_slice(&buf))?;
/*
if oldest_lsn == 0 || p.lsn < oldest_lsn {
oldest_lsn = p.lsn;
@@ -478,6 +478,6 @@ fn restore_wal(timeline: &dyn Timeline, timelineid: ZTimelineId, startpoint: Lsn
}
info!("reached end of WAL at {}", last_lsn);
let checkpoint_bytes = encode_checkpoint(checkpoint);
timeline.put_page_image(checkpoint_tag, Lsn(0), checkpoint_bytes);
timeline.put_page_image(checkpoint_tag, Lsn(0), checkpoint_bytes)?;
Ok(())
}
pageserver/src/waldecoder.rs
+26 -6
View File
@@ -273,7 +273,8 @@ pub struct DecodedBkpBlock {
/* Information on full-page image, if any */
has_image: bool, /* has image, even for consistency checking */
pub apply_image: bool, /* has image that should be restored */
pub will_init: bool,
pub will_init: bool, /* record intialize page content */
pub will_drop: bool, /* record drops relation */
//char *bkp_image;
hole_offset: u16,
hole_length: u16,
@@ -298,6 +299,7 @@ impl DecodedBkpBlock {
has_image: false,
apply_image: false,
will_init: false,
will_drop: false,
hole_offset: 0,
hole_length: 0,
bimg_len: 0,
@@ -795,7 +797,13 @@ pub fn decode_wal_record(checkpoint: &mut CheckPoint, record: Bytes) -> DecodedW
let mut blk = DecodedBkpBlock::new();
blk.forknum = pg_constants::PG_XACT_FORKNUM;
blk.blkno = buf.get_i32_le() as u32;
blk.will_init = true;
let info = xlogrec.xl_info & !pg_constants::XLR_INFO_MASK;
if info == pg_constants::CLOG_ZEROPAGE {
blk.will_init = true;
} else {
assert!(info == pg_constants::CLOG_TRUNCATE);
blk.will_drop = true;
}
trace!("RM_CLOG_ID updates block {}", blk.blkno);
blocks.push(blk);
} else if xlogrec.xl_rmid == pg_constants::RM_XACT_ID {
@@ -848,7 +856,13 @@ pub fn decode_wal_record(checkpoint: &mut CheckPoint, record: Bytes) -> DecodedW
let spcnode = buf.get_u32_le();
let dbnode = buf.get_u32_le();
let relnode = buf.get_u32_le();
//TODO handle this too?
let mut blk = DecodedBkpBlock::new();
blk.forknum = pg_constants::MAIN_FORKNUM;
blk.rnode_spcnode = spcnode;
blk.rnode_dbnode = dbnode;
blk.rnode_relnode = relnode;
blk.will_drop = true;
blocks.push(blk);
trace!(
"XLOG_XACT_COMMIT relfilenode {}/{}/{}",
spcnode,
@@ -921,7 +935,13 @@ pub fn decode_wal_record(checkpoint: &mut CheckPoint, record: Bytes) -> DecodedW
let spcnode = buf.get_u32_le();
let dbnode = buf.get_u32_le();
let relnode = buf.get_u32_le();
//TODO save these too
let mut blk = DecodedBkpBlock::new();
blk.forknum = pg_constants::MAIN_FORKNUM;
blk.rnode_spcnode = spcnode;
blk.rnode_dbnode = dbnode;
blk.rnode_relnode = relnode;
blk.will_drop = true;
blocks.push(blk);
trace!(
"XLOG_XACT_ABORT relfilenode {}/{}/{}",
spcnode,
@@ -1111,7 +1131,7 @@ pub fn decode_wal_record(checkpoint: &mut CheckPoint, record: Bytes) -> DecodedW
let mut blk = DecodedBkpBlock::new();
blk.forknum = pg_constants::PG_MXACT_OFFSETS_FORKNUM;
blk.blkno = blkno;
blk.will_init = true;
blk.will_drop = true;
blocks.push(blk);
}
let first_mbr_blkno =
@@ -1122,7 +1142,7 @@ pub fn decode_wal_record(checkpoint: &mut CheckPoint, record: Bytes) -> DecodedW
let mut blk = DecodedBkpBlock::new();
blk.forknum = pg_constants::PG_MXACT_MEMBERS_FORKNUM;
blk.blkno = blkno;
blk.will_init = true;
blk.will_drop = true;
blocks.push(blk);
}
} else {
pageserver/src/walreceiver.rs
+1 -1
View File
@@ -201,7 +201,7 @@ fn walreceiver_main(
let new_checkpoint_bytes = encode_checkpoint(checkpoint);
if new_checkpoint_bytes != old_checkpoint_bytes {
timeline.put_page_image(checkpoint_tag, Lsn(0), new_checkpoint_bytes);
timeline.put_page_image(checkpoint_tag, Lsn(0), new_checkpoint_bytes)?;
}
// Now that this record has been handled, let the page cache know that
// it is up-to-date to this LSN
pageserver/src/walredo.rs
-3
View File
@@ -445,9 +445,6 @@ impl PostgresRedoManagerInternal {
}
}
}
} else if info == pg_constants::XLOG_MULTIXACT_TRUNCATE_ID {
// empty page image indicates that this SLRU page is truncated and can be removed by GC
page.clear();
} else {
panic!();
}