* refactor gpload test file TEST.py

1. migrate gpload test to pytest
2. new function to form config file through yaml package and make it more reasonable
3. add a case to cover gpload update_condition arggument

* migrate gpload and TEST.py to python3.6
new test case 43 to test gpload behavior when column name has capital letters and without data type
change some ans file since psql react different

* change sql to find reuseable external table to make gpload compatible in gp7 and gp6
better TEST.py to write config file with ruamel.yaml moudle
Co-authored-by: NXiaoxiaoHe <hxiaoxiao@vmware.com>

Co-authored-by: NAshwin Agrawal <aashwin@vmware.com>
Co-authored-by: NJamie McAtamney <jmcatamney@vmware.com>

This commit makes several broad changes to address conversion issues common to
multiple utilities:

- The input and output of subprocess in Python 3 are now bytestrings instead
  of strings. Thus, some sanitizing of inputs and outputs is necessary

- Many built-in functions like raw_input and __cmp__ are deprecated in Python 3,
  and as a side effect list sorting and hashing work differently, requiring a
  different set of helper functions

- Implicit relative imports no longer work, so dbconn (in utilities code) and
  mgmt_utils (in test code) must be added to the search path and imported using
  a full path instead

- File objects require flush methods in python3, and popen2 has been deprecated
Co-authored-by: NJamie McAtamney <jmcatamney@vmware.com>
Co-authored-by: NTyler Ramer <tramer@vmware.com>

The subprocess32 package is a backport of Python 3 subprocess functionality to
Python 2, so with the upgrade to Python 3 it is no longer necessary.

This commit deletes the package from pythonSrc and changes import statements to
import subprocess directly, instead of falling back to it only if subprocess32
is not importable.
Co-authored-by: NJamie McAtamney <jmcatamney@vmware.com>
Co-authored-by: NTyler Ramer <tramer@vmware.com>

- Update Python file shebangs to use python3 and update gp_replicate_check and
  gpversion.py to allow running under Python 3

- Use Centos 7 dev containers with Python 3 and pip3 installed for testing, as
  prod containers do not yet work with Python 3, and update Travis with Python 3

- Install dependencies with pip3 to get Python 3-compatible versions

- Copy the Python 3 version of .so files, don't unset PYTHONHOME and PYTHONPATH,
  and don't remove built files from install locations, so that the Python 2 and
  Python 3 versions of various files can coexist
Co-authored-by: NJamie McAtamney <jmcatamney@vmware.com>
Co-authored-by: NKris Macoskey <kmacoskey@vmware.com>
Co-authored-by: NTyler Ramer <tramer@vmware.com>

The 2to3 utility is an officially-supported script to automatically convert
Python 2 code to Python 3.  It's not a complete fix by any means, but it
handles most basic syntax transformations and similar.

This commit is the result of running 2to3 against every Python file in the
gpMgmt directory, so it's quite large and fairly scattershot.  Manual updates
to any code that 2to3 can't handle will come in later commits.

* add double quatations when creating staging table
omit distribution key

* fix gpload fail when column names have capital letters in merge mode
Co-authored-by: NXiaoxiaoHe <hxiaoxiao@vmware.com>

This reverts commit 1060a425.

* fix gpload fail when capital letters in column name in merge mode

add double quotations in column names when create staging tables
omit distribution key
Co-authored-by: NXiaoxiaoHe <hxiaoxiao@vmware.com>

fix match column condition to resovle primary key conflict when using the gpload
merge mode to import data to the Multi-level partition table
fix fail when special char and capital letters in column names
Co-authored-by: NXiaoxiaoHe <hxiaoxiao@vmware.com>

The version of PyYAML vendored in gpMgmt/bin/ext is old, unmaintained,
and does not support python3. Actually, it does not even contain a
`__version__` attribute, so it is not possible to know the version.

We need to unvendor YAML and get to a library version that supports
python3 - for this reason, we are updating to the latest PyYAML
available.

Also update yaml.load to use yaml.safe_load instead.
Co-authored-by: NTyler Ramer <tramer@vmware.com>
Co-authored-by: NJamie McAtamney <jmcatamney@vmware.com>

This commit updates pygresql from 4.0.0 to 5.1.2, which requires
numerous changes to take advantages of the major result syntax change
that pygresql5 implemented. Of note, cursors or query objects
automatically cast returned values as appropriate python types - list of
ints, for example, instead of a string like "{1,2}". This is the bulk of
the changes.

Updating to pygresql 5.1.2 provides numerous benfits, including the
following:

- CVE-2018-1058 was addressed in pygresql 5.1.1

- We can save notices in the pgdb module, rather than relying on importing
the pg module, thanks to the new "set_notices()"

- pygresql 5 supports python3

- Thanks to a change in the cursor, using a "with" syntax guarentees a
  "commit" on the close of the with block.

This commit is a starting point for additional changes, including
refactoring the dbconn module.

Additionally, since isolation2 uses pygresql, some pl/python scripts
were updated, and isolation2 SQL output is further decoupled from
pygresql. The output of a psql command should be similar enough to
isolation2's pg output that minimal or no modification is needed to
ensure gpdiff can recognize the output.
Co-Authored-by: NTyler Ramer <tramer@pivotal.io>
Co-authored-by: NJamie McAtamney <jmcatamney@pivotal.io>

while gpload is loading data if the configure file contains "error_table" and doesn't contain "preload", an error of no attribute "staging_table" or "fast_path"  occurs.

gpload in the latest windows client package requires VS redistributable
package. Output more meaningful message if pg.py fails to load.

Co-authored-by: NRyan <ryan@chapterx.com>

For ETL user scenarios, there are some cases that may frequently create
and drop the same external table. And once the external table gets dropped.
All errors stored in the error log will lose.

To enable error log persistent for external with the same
"dbname"."namespace"."table".
Bring in "error_log_persistent" external table option. If create the
external table with `OPTIONS (error_log_persistent 'true')` and `LOG ERROR`,
the external's error log will be name as "dbid_namespaceid_tablename"
under "errlogpersistent" directory.
And drop external table will ignore to delete the error log.

Since GPDB 5, 6 still use pg_exttable's options to mark
LOG ERRORS PERSISTENTLY, so keep the ability for loading from
OPTIONS(error_log_persistent 'true').

Create separate `gp_read_persistent_error_log` function to read
persistent error log.
If the external table gets deleted, only the namespace owner
has permission to delete the error log.

Create separate `gp_truncate_persistent_error_log` function to delete
persistent error log.
If the external table gets deleted. Only the namespace owner has
permission to delete the error log.
It also supports wildcard input to delete error logs
belong to a database or whole cluster.

If drop an external table create with `error_log_persistent`. And then
create the same "dbname"."namespace"."table" external table without
persistent error log. It'll write errors to the normal error log.
The persistent error log still exists.
Reviewed-by: NHaozhouWang <hawang@pivotal.io>
Reviewed-by: NAdam Lee <ali@pivotal.io>

Add max_retries flag for gpload. It indicates the max times on connecting to GPDB timed out.
max_retries default value is 0 which means no retry.
If max_retries is -1 or other negative value, it means retry forever.

Test has been done manually.

External tables now use relkind='f', like all foreign tables. They have
an entry in pg_foreign_table, as if they belonged to a special foreign
server called "exttable_server". That foreign server gets special
treatment in the planner and executor, so that we still plan and execute
it the same as before.

* ALTER / DROP EXTERNAL TABLE is now mapped to ALTER / DROP FOREIGN TABLE.
  There is no "OCLASS_EXTTABLE" anymore. This leaks through to the user
  in error messages, e.g:

    postgres=# drop external table boo;
    ERROR:  foreign table "boo" does not exist

  and to the command tag on success:

    postgres=# drop external table boo;
    DROP FOREIGN TABLE

* psql \d now prints external tables as Foreign Tables.

Next steps:
* Use the foreign table API routines instead of special casing
  "exttable_server" everywhere.

* Get rid of the pg_exttable table, and store the all the options in
  pg_foreign_table.ftoptions instead.

* Get rid of the extra fields in pg_authid to store permissions to
  create different kinds of external tables. Store them as ACLs in
  pg_foreign_server.

The condition listed all possible values of relstorage, except for
'f' for RELSTORAGE_FOREIGN. The condition on relkind filters out foreign
tables as well, so the condition on relstorage is redundant. (Although
I don't think filtering out foreign table was even the intention here.)

GPload: change metadata query SQL to improvement performance
Old query SQL may take long time if catalog is large.

* Ship modified python module subprocess32 again

subprocess32 is preferred over subprocess according to python documentation.
In addition we long ago modified the code to use vfork() against fork() to
avoid some "Cannot allocate memory" kind of error (false alarm though - memory
is actually sufficient) on gpdb product environment that is usually with memory
overcommit disabled.  And we compiled and shipped it also but later it was just
compiled but not shipped somehow due to makefile change (maybe a regression).
Let's ship it again.

* Replace subprocess with our own subprocess32 in python code.

* Get gpdb version and support gpdb5 and gpdb6
* add gpversion.py into windows package

Setting a variable to itself is a no-op which can be removed. This
may have been introduced in error and instead masking a real bug,
but if it so then we have lived with it for two years so I'm opting
for removing.

Reviewed-by: Asim R P and Bhuvnesh Chaudhary

We don't support Greenplum on these platforms.

Some files (e.g. Makefile.{hpux,solaris}) have been left in place
because they are upstream postgres files. Removing them isn't
worth the headache it would cause when merging commits from
postgres.
Authored-by: NBen Christel <bchristel@pivotal.io>

This is in preparation for adding operator classes as a new column
(distclass) to gp_distribution_policy. This naming is consistent with
pg_index.indkey/indclass. Change the datatype to int2vector, also for
consistency with pg_index, and some other catalogs that store attribute
numbers, and because int2vector is slightly more convenient to work with
in the backend. Move the column to the end of the table, so that all the
variable-length and nullable columns are at the end, which makes it
possible to reference the other columns directly in Form_gp_policy.

Add a backend function, pg_get_table_distributedby(), to deparse the
DISTRIBUTED BY definition of a table into a string. This is similar to
pg_get_indexdef_columns(), pg_get_functiondef() etc. functions that we
have. Use the new function in psql and pg_dump, when connected to a GPDB6
server.
Co-authored-by: NHeikki Linnakangas <hlinnakangas@pivotal.io>
Co-authored-by: NPeifeng Qiu <pqiu@pivotal.io>
Co-authored-by: NAdam Lee <ali@pivotal.io>

This removes a duplicate import and a few set, but never used, vars
from the gpload.py code as well as the including_defaults token as
it was clearly unused.

Also fixes a few typos while in there, one of which is a user facing
error message.
Reviewed-by: NJacob Champion <pchampion@pivotal.io>

The Greenplum specific error handling via ereport()/elog() calls was
in need of a unification effort as some parts of the code was using a
different messaging style to others (and to upstream). This aims at
bringing many of the GPDB error calls in line with the upstream error
message writing guidelines and thus make the user experience of
Greenplum more consistent.

The main contributions of this patch are:

* errmsg() messages shall start with a lowercase letter, and not end
  with a period. errhint() and errdetail() shall be complete sentences
  starting with capital letter and ending with a period. This attempts
  to fix this on as many ereport() calls as possible, with too detailed
  errmsg() content broken up into details and hints where possible.

* Reindent ereport() calls to be more consistent with the common style
  used in upstream and most parts of Greenplum:

	ereport(ERROR,
			(errcode(<CODE>),
			 errmsg("short message describing error"),
			 errhint("Longer message as a complete sentence.")));

* Avoid breaking messages due to long lines since it makes grepping
  for error messages harder when debugging. This is also the de facto
  standard in upstream code.

* Convert a few internal error ereport() calls to elog(). There are
  no doubt more that can be converted, but the low hanging fruit has
  been dealt with. Also convert a few elog() calls which are user
  facing to ereport().

* Update the testfiles to match the new messages.

Spelling and wording is mostly left for a follow-up commit, as this was
getting big enough as it was. The most obvious cases have been handled
but there is work left to be done here.

Discussion: https://github.com/greenplum-db/gpdb/pull/6378Reviewed-by: NAshwin Agrawal <aagrawal@pivotal.io>
Reviewed-by: NHeikki Linnakangas <hlinnakangas@pivotal.io>

Reviewed-by: NJacob Champion <pchampion@pivotal.io>
Reviewed-by: NJimmy Yih <jyih@pivotal.io>

While == None works for comparison, it's a wasteful operation as it
performs type conversion and expansion. Instead move to using the
"is" operator which is the documented best practice for Python code.

Reviewed-by: Jacob Champion

* Add external table encoding option as condition of finding reusable table

Get database default encoding if ENCODING is not set in config file.
Find encoding code by encoding string and then add encoding code as one of
conditions of finding reusable table.

gpload test case will run gpload with subprocess, read stdout
and stderr from it and wait for exit. sys.exit in gpload does some
cleanup may cause deadlock between test and gpload. os._exit will
exit immediately, but we need to flush stdout and stderr before
that.

- The results of fast_match SQL don't include shema name, so we need
add shema name to extSchemaTable for fast_match
- Remove locationStr which is unused.

- add fast_match option in gpload config file. If both reuse_tables
and fast_match are true, gpload will try fast match external
table(without checking columns). If reuse_tables is false and
fast_match is true, it will print warning message.

The pg_exttable.fmterrtbl column stored the OID of the error table, but
without an error table it is just set to the OID of the external table.
That is not necessary, there are other columns which indicate if error
logging is enabled. Therefore this column can be removed.

When gpload finishes its query, it will send SIGTERM to gpfdist.
gpfdist handle SIGTERM with exit(1), which will invoke registered
apr handlers and cleanup all apr resources including apr_pool. If
this happens just during normal destruction of apr_pool in
do_close, gpfdist will hang.

Call _exit in gpfdist to avoid any cleanup handlers, and let gpload
send SIGKILL to perform hard kill.

- if the data file contains "\N" as the delimiter, it would not be
recognized properly by gpload
- root cause: gpload replace the quote in nullas option as well as
replace '\' as '\\'
- solution: add quote_no_slash function to handle nullas option