Troubleshooting
Problem
ERROR: 100 : limit reached on number of concurrent host channels and the following fix has already been applied: Changed parameter maxFlowCommChannels to 300. Issue still there.
Symptom
ERROR: 100 : limit reached on number of concurrent host channels
Cause
Too many queries ran at the same time or the query is asking for redundant information.
Environment
NPS 7.2.x
Diagnosing The Problem
ERROR: 100 : limit reached on number of concurrent host channels and the following fix has already been applied:
Changed parameter maxFlowCommChannels to 300.
Issue still there.
Resolving The Problem
Increase the value of INLIST_TRESHOLD. If we do:
- 20 broadcasted temporary table created during this query execution
will disappear,
- 20 ExistsJoinNode's in Snippet 2 will disappear,
- row count estimate will improve.
PE recommends making INLIST_THRESHOLD 15. It should
be done globally, by putting the following line in the
/nz/data/postgresql.conf file:
inlist_threshold = 15
To enable the global change, run
pkill -HUP postmaster
or just nzstop/nzstart.
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Document Information
Modified date:
17 October 2019
UID
swg21972283