LPDLST parameter

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Length of user push down list


Default value
  5000 (version 7.4 and earlier)
10000 (version 7.5 and later)
Parameter type
Where set
On user's parameter line or reset by UTABLE command
Related products
Model 204 V2.2 or earlier


The length of the user pushdown list, a work area used for Model 204 program flow control

LPDLST can range from:

  • 5000 to 32760 (version 7.4 and earlier)
  • 10000 to 65536 (version 7.5 and later)

LPDLST is set to the minimum value by default.

Its recommended initial value for SQL processing is the maximum.

You can monitor LPDLST use with the PDL audit trail statistic.

You might need to increase LPDLST in the following cases:

  • Complex C patterns. LPDLST also includes some space for the C pattern matcher processing. Complex patterns (for example, patterns involving nested repeated patterns or nested wildcards) might overflow the LPDLST area and require you to increase the LPDLST setting to 32K.
  • Unrecoverable errors when running User Language requests. You might need to increase the size of LPDLST (by approximately 10-20%, depending on your environment and the applications being run) and/or the LQTBL parameter.
  • Checkpointing (31-bit O/S). Because checkpointing is asynchronous in 31-bit operating systems, you might need to increase LPDLST in such environments.
  • Allowing for SEQPDL. The SEQPDL parameter, by default, adds an additional 3072 bytes to the free space set aside in the user pushdown list. If your applications currently use most of the area that you specified with LPDLST, to avoid an ERROR 2126 USER'S PUSHDOWN LIST OVERFLOWED you might need to increase LPDLST by up to 3072 bytes, or more if you reset SEQPDL to a larger value.