Hi,
So first I'm a pgsql hacker newbie and I've been reading up on the storage structure: http://www.postgresql.org/docs/8.2/interactive/storage-page-layout.html I'm trying to recover deleted records from a page file (postgresql 8.2) : i.e. base/dbId/20132 I am able to successfully read all the header data I need (PageHeaderData, ItemIdData , HeapTupleHeaderData) but I hit a wall when I try to start reading user data. This has helped: http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/postgres.h?rev=1. 77;content-type=text%2Fplain I've read and understood fairly well how varlena structures are stored (plain, compressed, external/toast) but so far I can't seem to read a plain inline value. I think part of my problem is I haven't really understood what 'Then make sure you have the right alignment' means. My approach currently is: After reading HeapTupleHeaderData (23 bytes), I advance another 4 bytes (hoff) and try to read a 32 bit integer (first attribute). I am expecting to get an integer value 1 but I get 512 . Am I doing this wrong? Could someone point me to the pgsql code pieces I should be looking at? If useful, this is the information I have before reading the 'user data': object(PostgreSQL_HeapTupleHeaderData)#14 (7) { ["xmin"]=> string(5) "13824" ["xmax"]=> string(1) "0" ["cid"]=> string(1) "0" ["ctid"]=> object(PostgreSQL_ItemPointerData)#16 (2) { ["blockId"]=> string(1) "0" ["posId"]=> int(0) } ["infomask2"]=> int(0) ["infomask"]=> int(2) ["hoff"]=> int(4) } object(PostgreSQL_Attribute)#7 (6) { ["name"]=> string(7) "book_id" ["relid"]=> int(20132) ["len"]=> int(4) ["num"]=> int(1) ["ndims"]=> int(0) ["align"]=> string(1) "i" } array(1) { ["book_id"]=> int(512) }
