we experimented with issuing the same query repeatedly, and we observed a slow down not only on the first query
I am not sure what the reasons are, perhaps you can enable TRACE log to find what leads to slow,  I guess that some meta information is reloaded under highly write workload.

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   Jaanai Zhang
   Best regards!



William Shen <willshen@marinsoftware.com> 于2019年2月1日周五 上午2:09写道:
Thanks Jaanai. Do you know if that is expected only on the first query against a table? For us, we experimented with issuing the same query repeatedly, and we observed a slow down not only on the first query. Does it make sense to preemptively load table metadata on start up to warm up the system to reduce latency during the actual query time (if it is possible to do so)?

On Wed, Jan 30, 2019 at 10:54 PM Jaanai Zhang <cloud.poster@gmail.com> wrote:
It is expected when firstly query tables after establishing the connection. Something likes loads some meta information into local cache that need take some time,  mainly including two aspects: 1. access SYSTEM.CATALOG table to get schema information of the table  2. access the meta table of HBase to get regions information of the table

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   Jaanai Zhang
   Best regards!



William Shen <willshen@marinsoftware.com> 于2019年1月31日周四 下午1:37写道:
Hi there,

I have a component that makes Phoenix queries via the Phoenix JDBC Connection. I noticed that consistently, the Phoenix Client takes longer to execute a PreparedStatement and it takes longer to read through the ResultSet for a period of time (~15m) after a restart of the component. It seems like there is a warmup period for the JDBC connection. Is this to be expected?

Thanks!