Support Article
ORA-01555 on running Business Intelligence Exchange extract rule
SA-61312
Summary
ORA-01555 error occurs when executing Business Intelligence Exchange (BIX) extract rules.
Error Messages
Error: SQL error while reading the blob: errorCode = 1555 errorMessage:ORA-01555: snapshot too old: rollback segment number with name "" too small
Steps to Reproduce
Execute a BIX extract rule.
Root Cause
A defect or configuration issue in the operating environment. BIX extract is run during production hours or when the data records required by the reader for consistent read are overwritten by other writers.
Resolution
Here’s the explanation for the reported behavior:
This error occurs when the query executing tenure is large while the undo_retention is comparatively small. In such cases, perform one of the following local-changes:
- Increase the value for the database setting of UNDO_RETENTION
- Schedule the BIX extract during off-hours when there are few users updating the same Work Orders that are extracted
- Analyze the query and add appropriate indexes, and run smaller extractions in parallel to minimize the total extraction time
https://community.pega.com/support/support-articles/bix-version-231-snapshot-too-old-error
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Published July 25, 2018 - Updated December 2, 2021
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