APAR status
Closed as documentation error.
Error description
If your row size is over 32000 bytes. ONLINE-CDC will split the CDC record being return, limiting ifx_lo_read() to fetch only 32000 bytes and the application developer must recognize that this is a partial record and fetch the rest of the record with another call to ifx_lo_read(). This behavior is not documented and appears to be a design issue with the Informix implementation of the CDC API. The only way a developer would know to do this is to reference the example provided in the cdcapi.ec
Local fix
Review cdcapi.ec and when a partial record is retrieved you must retrieve the rest of the record with another call to ifx_lo_read()
Problem summary
**************************************************************** * USERS AFFECTED: * * Users of the Informix log capture API (CDC) * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Refer to the cdcapi.ec sample program in the * * $INFORMIXDIR/demo/cdc directory. Informix versions * * 12.10.xC4 and later also remove an internal constraint that * * in this case limited the amount of data returned in a single * * read call to approximately 32 KB. * ****************************************************************
Problem conclusion
Your application cannot depend on a specific number of records being returned by smart large object read calls. The number of CDC records that are returned in a read call is not predictable and might not be an integral number. If a read call returns only part of a CDC record, the next read call returns more data for that record. Your application must merge the parts of the record that are returned in multiple read calls. The Change Data Capture sample program provides examples of merging parts of records.
Temporary fix
Comments
APAR Information
APAR number
IT00258
Reported component name
INFORMIX SERVER
Reported component ID
5725A3900
Reported release
C10
Status
CLOSED DOC
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2014-03-12
Closed date
2014-11-07
Last modified date
2014-11-07
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Applicable component levels
[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSGU8G","label":"Informix Servers"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"C10","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]
Document Information
Modified date:
07 November 2014