15.00 - Computing the Restart Log Table Requirements - MultiLoad

Teradata MultiLoad Reference

prodname
MultiLoad
vrm_release
15.00
category
Programming Reference
featnum
B035-2409-034K

Computing the Restart Log Table Requirements

The space requirements of a Teradata MultiLoad restart log table are highly dependent on the specifics of the job. Although there are mandatory inserts for every Teradata MultiLoad job, others occur on a job-dependent basis.

Following is an example of the table definition for a Teradata MultiLoad restart log table, which is automatically created by Teradata MultiLoad:

CREATE TABLE SFD.samplelog ,FALLBACK ,
     NO BEFORE JOURNAL,
     NO AFTER JOURNAL
     (
      LogType INTEGER,
      Seq INTEGER,
      ReqRC INTEGER,
      ReqType INTEGER,
      ReqLen INTEGER,
      ReqMsg VARCHAR(255),
      SysInfo VARBYTE(255),
      MiscInt1 INTEGER,
      MiscInt2 INTEGER,
      MiscInt3 INTEGER,
      MiscInt4 INTEGER,
      MiscInt5 INTEGER,
      MiscInt6 INTEGER,
      MiscInt7 INTEGER,
      MiscInt8 INTEGER,
      MLoadSeq INTEGER DEFAULT 0 ,
      MLoadImpSeq INTEGER,
      MLoadSrcSeq INTEGER,
      MLoadCkpt VARBYTE(255),
      RunDate DATE DEFAULT DATE ,
      RunTime FLOAT DEFAULT TIME )
      UNIQUE PRIMARY INDEX( LogType ,Seq ,MLoadSeq );

From the table definition, the size of each row depends on the VARCHAR length, which can range from 0 to a maximum of 255:

  • If the VARCHAR length is 0, then the size of each row is 82 bytes.
  • If the VARCHAR length is 255, then the size of each row is 847 bytes.
  • The possible inserts for this table are as follows:

  • Seven mandatory inserts:
  • Three inserts, one each, upon entry to the DML phase, the acquisition phase, and the application phase
  • One insert to mark the end of a Teradata MultiLoad task
  • Three inserts, one each, to mark the dropping of the ET and UT error tables, and the WT work tables
  • One insert for each Teradata SQL statement processed (for example, CREATE TABLE, DROP TABLE)
  • One insert for each input data checkpoint
  • Using these guidelines provides an estimate of 260 KB of space required for the example restart log table:

     

    These calculations estimate that 260 K of space would probably suffice for the restart log table of the example job. Use a similar computation to estimate the requirements for the Teradata MultiLoad job.