paul-rogers edited a comment on issue #1873: DRILL-6096: Provide mechanism to 
configure text writer configuration
URL: https://github.com/apache/drill/pull/1873#issuecomment-544277734
 
 
   General question: the idea of giving the user more control is a good one. 
I'm seeing this need in multiple of recent plugins. I wonder, however, if we 
should offer a more scalable solution?
   
   We currently have plugin, session, config and table function options all 
which control some aspect of reading and writing. The plugin and config options 
really want to be "bulk" or "slow moving" settings: set them once for a system 
or file format.
   
   Session options have two problems. First, they introduce client state: they 
must be set and reset around each query that needs them. This prevents load 
balancing and fail-over. (By contrast, Impala keeps options in the client and 
sends them to the server on each query, allowing unlimited load balancing via 
round-robin and allows transparent fail over.)
   
   Further, session options are awkward for many tools: in addition to running 
a query, the client must send `ALTER SESSION` statements which are somehow 
associated with that query. Easy for our unit tests, not so easy for most BI 
tools.
   
   Table options look like what we want, but they have a number of issues, 
including that, when used, they "erase" any options set in the format plugin.
   
   Then, consider usability. Suppose I set the options and write a text file. 
What do I have to do to query that file I just wrote? Configure a specialized 
format plugin? Use table options? Seems we really need a more stable, mature 
solution; we're past the time where we can get away with workarounds.
   
   Is there some other solution we could consider? Better table options? Some 
syntax that allows setting of options in the query? Some kind of view or schema 
that encapsulates these options so that they don't have to be provided on every 
query?
   
   I don't have a solid suggestion; I'm simply pointing out the ease-of-use 
issue.
   

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