Need help with decoding of sql array from WAL files version 7.4.17 - Mailing list pgsql-general

From Andrey Stoev
Subject Need help with decoding of sql array from WAL files version 7.4.17
Date
Msg-id 20080207122335.EEFC41CD0003@simrevolution.webscience.it
Whole thread Raw
List pgsql-general

I need to restore two records from a lost transaction and I am having only the WAL file, managed by Postgresql 7.4.17. The structure of records is:

 * Record 1: varchar(400)[] with exact 191 elements, where al least 185 elements are just “*” and at most 6 are string with length>1. Like this {first string,*,*,*,*,*,second string,…}

 * Record 2: smallint[] with exact 191 elements, where every element is between [-1 and 8]. Like this {-1,0,7,3,-1,-1,3,4,5,…}

 

Can anybody give me more information about the implementation of SQL arrays like:

1)       hex markers for the beginning, length, or ending of the array

2)       way of encoding strings inside the array

3)       some idea in which interval should be the size of the encoded array. Should be correct if I say that my first record is more than 191 bytes or not?

4)       particular documentation for sql array encoding in the 7.4.17 implementation

 

10x in advance for any answer!

---

Andrew

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