ORC or not ORC?

[M Murphy]

Hello,

I am seeing conflicting information about whether cstore uses ORC.  The README proclaims ORC very prominently:

"""

This extension uses the Optimized Row Columnar (ORC) format for its data layout. ORC improves upon the RCFile format developed at Facebook, and brings the following benefits:

"""

but this post from a couple of years ago says that it is not ORC:  https://groups.google.com/forum/#!searchin/cstore-users/orc/cstore-users/88D9v_d6Ojc/aDqLwKidFlEJ

I went through the pain of installing hive and ran --orcfiledump in the hope of understanding why the cstore was using up so much memory, however that threw a format error.  That suggests that the mailing list post is right and the README is wrong.  Is that correct?  If so, what other diagnostic tools are there?

Best wishes, Max

[Murat Tuncer]

It is like ORC, but not exactly ORC.  https://github.com/citusdata/cstore_fdw/wiki/CStore-File-Layout describes how data is laid out.

we do not have a diagnostics tool to examine data file at this time. What would you like to do ?