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Informix Error -264

-264 Could not write to a temporary file.

The database server created a temporary file in the directory that the DBTEMP environment variable (or /tmp by default on UNIX systems) specifies, but it encountered an error when it tried to write data into the file. To determine the cause of this error, check the accompanying ISAM error code and look for operating-system error messages that might give more invormation. Possible causes include: hardware failure, a full disk, or, if PDQ is enabled, insufficient shared memory.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-264 is the write-side sibling of -230's temp-file read failure — the file was created successfully in the DBTEMP-specified (or default /tmp) directory, but writing to it failed. The official text adds one cause specific to this error: PDQ-related shared memory exhaustion.

  1. Hardware failure affecting the temp file's underlying storage.
  2. A full disk in the temp directory.
  3. Insufficient shared memory, if PDQ (Parallel Database Query) is enabled. This is a distinct cause from -229/-230's usual space/permissions/cleanup-utility causes — PDQ's parallel execution can demand more shared memory for temp-file operations than a serial execution path would need.
Solutions / Resolution
  1. Check the accompanying ISAM error code and OS-level messages first.
  2. Check disk space and hardware health in the temp directory.
  3. If PDQ is enabled, check shared memory configuration and availability — this is the distinguishing cause to investigate here that doesn't apply to -229/-230.
  4. Consider adjusting PDQPRIORITY or shared memory sizing if PDQ's resource demands are the actual cause — either reduce parallelism for the specific query, or increase shared memory allocation if the workload genuinely needs it.
Examples
Checking PDQ involvement
-- Check whether PDQ is active for the failing query/session
SET PDQPRIORITY 0;
-- retry — if this succeeds where the PDQ-enabled version failed,
-- shared memory pressure from parallelism was likely the cause
The usual space check
df -h /tmp
Diagnostic Checks
  1. Check the accompanying ISAM error code.
  2. Check disk space and hardware health.
  3. Check whether PDQ was enabled for the failing operation, and review shared memory configuration if so.
Related Errors / Related Topics
  • -230 — "Could not read a temporary file." The read-side sibling — same general temp-file mechanics, without the PDQ-specific shared-memory cause.
  • -229 — "Could not open or create a temporary file." Another member of the same temp-file trio.

If PDQ is enabled for the failing operation, check shared memory pressure before assuming a simple disk-space or hardware issue — that's the cause specific to this error.