Hi, On Tue, Aug 28, 2018 at 11:21:34AM +0200, Peter Eisentraut wrote: > This is reproducible with PG11 and PG12: > > initdb -k data > postgres -D data > > make installcheck > # shut down postgres with Ctrl-C > > pg_verify_checksums data > > pg_verify_checksums: checksum verification failed in file > "data/base/16384/28647", block 65: calculated checksum DC70 but expected 0 > pg_verify_checksums: checksum verification failed in file > "data/base/16384/28649", block 65: calculated checksum 89D8 but expected 0 > pg_verify_checksums: checksum verification failed in file > "data/base/16384/28648", block 65: calculated checksum 9636 but expected 0 > Checksum scan completed > Data checksum version: 1 > Files scanned: 2493 > Blocks scanned: 13172 > Bad checksums: 3 > > The files in question correspond to > > hash_i4_index > hash_name_index > hash_txt_index > > Discuss. ;-)
I took a look at hash_name_index, assuming the others are similar. Page 65 is the last page, pageinspect barfs on it as well: regression=# SELECT get_raw_page('hash_name_index', 'main', 65); WARNING: page verification failed, calculated checksum 18066 but expected 0 ERROR: invalid page in block 65 of relation base/16384/28638 The pages before that one from page 35 on are empty: regression=# SELECT * FROM page_header(get_raw_page('hash_name_index', 'main', 1)); lsn | checksum | flags | lower | upper | special | pagesize | version | prune_xid -----------+----------+-------+-------+-------+---------+----------+---------+----------- 0/422D890 | 8807 | 0 | 664 | 5616 | 8176 | 8192 | 4 | 0 (1 Zeile) [...] regression=# SELECT * FROM page_header(get_raw_page('hash_name_index', 'main', 34)); lsn | checksum | flags | lower | upper | special | pagesize | version | prune_xid -----------+----------+-------+-------+-------+---------+----------+---------+----------- 0/422C690 | 18153 | 0 | 580 | 5952 | 8176 | 8192 | 4 | 0 (1 Zeile) regression=# SELECT * FROM page_header(get_raw_page('hash_name_index', 'main', 35)); lsn | checksum | flags | lower | upper | special | pagesize | version | prune_xid -----+----------+-------+-------+-------+---------+----------+---------+----------- 0/0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 [...] regression=# SELECT * FROM page_header(get_raw_page('hash_name_index', 'main', 64)); lsn | checksum | flags | lower | upper | special | pagesize | version | prune_xid -----+----------+-------+-------+-------+---------+----------+---------+----------- 0/0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 regression=# SELECT * FROM page_header(get_raw_page('hash_name_index', 'main', 65)); WARNING: page verification failed, calculated checksum 18066 but expected 0 ERROR: invalid page in block 65 of relation base/16384/28638 Running pg_filedump on the last two pages results in (not sure the "Invalid header information." are legit; neither about the checksum failure on block 64): mba@fock:~/[...]postgresql/build/src/test/regress$ ~/tmp/bin/pg_filedump -R 64 65 -k -f tmp_check/data/base/16384/28638 --8<-- ******************************************************************* * PostgreSQL File/Block Formatted Dump Utility - Version 10.1 * * File: tmp_check/data/base/16384/28638 * Options used: -R 64 65 -k -f * * Dump created on: Tue Aug 28 14:53:37 2018 ******************************************************************* Block 64 ******************************************************** <Header> ----- Block Offset: 0x00080000 Offsets: Lower 0 (0x0000) Block: Size 0 Version 0 Upper 0 (0x0000) LSN: logid 0 recoff 0x00000000 Special 0 (0x0000) Items: 0 Free Space: 0 Checksum: 0x0000 Prune XID: 0x00000000 Flags: 0x0000 () Length (including item array): 24 Error: Invalid header information. Error: checksum failure: calculated 0xc66a. 0000: 00000000 00000000 00000000 00000000 ................ 0010: 00000000 00000000 ........ <Data> ------ Empty block - no items listed <Special Section> ----- Error: Invalid special section encountered. Error: Special section points off page. Unable to dump contents. Block 65 ******************************************************** <Header> ----- Block Offset: 0x00082000 Offsets: Lower 24 (0x0018) Block: Size 8192 Version 4 Upper 8176 (0x1ff0) LSN: logid 0 recoff 0x04229c20 Special 8176 (0x1ff0) Items: 0 Free Space: 8152 Checksum: 0x0000 Prune XID: 0x00000000 Flags: 0x0000 () Length (including item array): 24 Error: checksum failure: calculated 0x4692. 0000: 00000000 209c2204 00000000 1800f01f .... ."......... 0010: f01f0420 00000000 ... .... <Data> ------ Empty block - no items listed <Special Section> ----- Hash Index Section: Flags: 0x0000 () Bucket Number: 0xffffffff Blocks: Previous (-1) Next (-1) 1ff0: ffffffff ffffffff ffffffff 000080ff ................ *** End of Requested Range Encountered. Last Block Read: 65 *** --8<-- So it seems there is some data on the last page, which makes the zero checksum bogus, but I don't know anything about hash indexes. Also maybe those empty pages are not initialized correctly? Or maybe the "Invalid special section encountered" error meand pg_filedump cannot handle hash indexes completely. In any case, I am not sure pg_verify_checksums is at fault here. Michael -- Michael Banck Projektleiter / Senior Berater Tel.: +49 2166 9901-171 Fax: +49 2166 9901-100 Email: michael.ba...@credativ.de credativ GmbH, HRB Mönchengladbach 12080 USt-ID-Nummer: DE204566209 Trompeterallee 108, 41189 Mönchengladbach Geschäftsführung: Dr. Michael Meskes, Jörg Folz, Sascha Heuer Unser Umgang mit personenbezogenen Daten unterliegt folgenden Bestimmungen: https://www.credativ.de/datenschutz