Compressing BLOB Fields

Delphi Database, Delphi Components from ComponentAce

Compressing BLOB Fields

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Absolute Database is capable to compress data stored in the BLOB (Binary Large OBject) fields.
This option can significantly reduce database file size when you need to store large texts, RTFs, bitmap images or other binary data in the database table.

BLOB field values are compressed / decompressed on-the-fly.
Everything you need to do is just to specify the BLOB compression settings for appropriate table fields.

BLOB compression settings could be specified independently for each BLOB field:

BlobCompressionAlgorithm

BlobCompressionMode

Example:

  with ABSTable1 do
   begin
     {specifying advanced field definitions}
     with AdvFieldDefs do
      begin
       Clear;
       Add('EmpNo',aftAutoInc,0,False);
       Add('Name',aftString, 100, False);

       {ZLib compression algorithm with the fastest compression mode}
       Add('Text',aftMemo, 0, False, caZLIB, 1);
      end;
     CreateTable;
   end;

Note:   To change Blob compression settings in existing table, perform Restructure table operation.

Nov 21, 2024