Follow src/pl/plpython/README.md to see how to build
 and use plpython3u on GPDB.
Co-authored-by: NYandong Yao <yyao@pivotal.io>

* Update readme instructions for using docker for building GPDB

Adding support to create cluster for tinc testing. This also create
gptest database. Here is an example script to run tinc tests:

```
cd ~/workspace/gpdb
source .../greenplum_path.sh
make create-tinc-test-cluster
source gpAux/gpdemo/gpdemo-env.sh
make -C src/test/tinc walrep_2 # to run walrep_2 tinc tests
```

Author: Xin Zhang <xzhang@pivotal.io>
Author: Ashwin Agrawal <aagrawal@pivotal.io>

This patch removes codegen wholesale from Greenplum.

In addition to reverting the commits involving codegen, we also removed
miscellaneous references to the feature and GUC.

The following commits from 5.0.0 were reverted (topologically ordered):

f38c9064 Support avg aggregate function in codegen
87dcae4c Capture and print error messages from llvm::verifyFunction
65137540 libgpcodegen assert() overrides use GPDB Assert()
81d378b4 GenerateExecVariableList calls regular slot_getattr when the code generation of the latter fails
05a28211 Update Google Test source path used by codegen
22a35fcc Call ereport when code generating float operators
79517271 Support overflow checks for doubles.
b5373a1e Fix codegen unittest link problem
7a1a98c9 Print filename and lineno in codegened CreateElog
58eda293 Fix wrong virtual tuple check in codegened slot_getattr
bc6faa08 Set llvm_isNull_ptr to false when the result of codegened expression evaluation is not null
8bbbd63f Enhance codegened advance_aggregates with support for null attributes
e1fd6072 Abort code generation of expression evaluation trees with unsupported ExprState types
509460ee Support null attributes in codegen expression evaluation framework
739d978d Move enrollment of codegened ExecVariableList to ExecInitNode
c05528d1 Fix CHECK_SYMBOL_DEFINED macro in CMakeLists.txt
12cfd7bd Support offset calculation when there is null in the tuple and codegen is enabled
40a2631e Use slot_getattr wrapper function for regular version.(#1194)
613e9fbb Revert "Fix codegen issue by moving slot_getattr to heaptuple.c similar to"
ee03f799 Fix cpplint error on advance aggregate
2a65b0aa Fix slot function nullptr issue in expr eval.
3107fc0e Fix for !(expr1 & expr2) and hasnull logic in slot_getatrr codegen.
c940c7f6 Fix codegen issue by moving slot_getattr to heaptuple.c similar to Postgres.
c8125736 Introduce guc to enable/disable all generator.
a4f39507 Ensure that codegen unittests pass with GCC 6.2.0 (#1177)
682d0b28 Allow overriding assert() functionality in libgpcodegen in DEBUG mode
3209258a Organize codegen source files and unit tests
d2ba88a9 Fix codegen unittests using DatumCastGenerator
020b71a5 Generate code for COUNT aggregate function
0eeec886 Fixing codegen related bugs in InitializeSupportedFunction
41055352 Rewrite PGGenericFuncGenerator to support variable number of types
e5318b6b Add AdvanceAggregatesCodegenEnroll mock function
87521715 Codegen advance_aggregates for SUM transition function
2043d95b Use string messages in codegened slot_getattr fallback block
f160fa5a Add new GUC to control Codegen Optimization level.
697ffc1a Fix cpplint errors
c5e3aed4 Support Virtual Tuples and Memtuples in SlotGetAttrCodegen
5996aaa7 Keep a reference to the CodegenManager in code generators
6833b3c2 Remove unused header and just include what you use in codegen
ab1eda87 Allow setting codegen guc to ON only if code generation is supported by the build
dcd40712 Use PGFuncGeneratorInfo to codegen pg functions
83869d1c Replace dynamic_cast with dyn_cast for llvm objects
23007017 Decide what to generate for ExecEvalExpr based on PlanState
387d8ce8 Add EXPLAIN CODEGEN to print generated IR to the client
c4a9bd27 Introduce Datum to cpp cast, cpp type to Datum cast  and normal cast.(#944)
66158dfd Record external function names for useful debugging
adab9120 Support variable length attributes in SlotGetAttrCodegen.
335e09aa Proclaim that the codegen'ed version of generated functions are called in debug build
50fd9140 Fix cpplint errors
88a04412 Use ExprTreeGeneratorInfo for expression tree generation.
3b4af3bb Split code generation of ExecVariableList from slot_getattr
8cd9ed9f Support <= operator for date/timestamp data types and some minor refactors.
e4dccf46 Implement InlineFunction to force inline at call site
71170942 Mock postmaster.o for codegen_framework_unittest.t
09f00581 Codegen expressions that contain plus, minus and mul operators on float8 data types
d7fb2f6d Fix codegen unittests on Linux and various compiler warnings while building codegen.
45f2aa96 Fix test and update coding style This closes #874
1b26fbfc Enrolled targetlist for scan and aggregate
ebd1d014 Enhance codegen framework to support arbitrary expr tree
ec626ce6 Generate and enroll naive ExecEvalExpr in Scan's quals
1186001e Revert "Create naive code-generated version of ExecQual"
6f928a65 Replace RegisterExternalFunction with GetOrRegisterExternalFunction using an unordered_map in codegen_utils
6ae0085b Move ElogWrapper to GpCodegenUtils.
d3f80b45 Add verifyfunction for generated llvm function.
7bcf094a Fix codegen compiler error with 8.3 merge
aae0ad3d Create naive code-generated version of ExecQual
dce266ad Minor code quality fixes in src/backend/codegen
d281f340 Support null attributes in code generated ExecVariableList
82fd418e Address a number of cpplint errors in codegen_utils_unittest.cc
887aa48d Add check for CodegenUtils::GetType for bool arrays
bb9b92c6 Enhance Base Codegen to do clean up when generation fails
b9ef5e3f Fix build error for Annotated types
a5cfefd9 Add support for array types in codegen_utils.
2b883384 Fix static_assert call
7b75d9ea This commit  generates code for code path: ExecVariableList > slot_getattr > _slot_getsomeattrs > slot_deform_tuple. This code path is executed during scan in simple select queries that do not have a where clause (e.g., select bar from foo;).
6d0a06e8 Fix CodeGen typos and CodeGeneratorManagerCreate function signature in gpcodegen_mock.c
4916a606 Add support for registering vararg external functions with codegen utils.
ae4a7754 Integrate codegen framework and make simple external call to slot deform tuple. This closes #649
ee5fb851 Renaming code_generator to codegen_utils and CodeGenerator to CodegenUtils. This closes #648
88e9baba Adding GPDB code generation utils
Signed-off-by: NJesse Zhang <sbjesse@gmail.com>
Signed-off-by: NMelanie Plageman <mplageman@pivotal.io>
Signed-off-by: NSambitesh Dash <sdash@pivotal.io>

Signed-off-by: NLarry Hamel <lhamel@pivotal.io>

- README.ubuntu.bash and README.centos.bash are created
for different dev-setup environments
Signed-off-by: NLarry Hamel <lhamel@pivotal.io>

    commit b0328d5631088cca5f80acc8dd85b859f062ebb0
    Author: mcdevc <a@b>
    Date:   Fri Mar 6 16:28:45 2009 -0800

        Separate our internal libpq front end from the client libpq library
        upgrade libpq to the latest to pick up bug fixes and support for more
        client authentication types (GSSAPI, KRB5, etc)
        Upgrade all files dependent on libpq to handle new version.

Above is the initial commit of gp_libpq_fe, seems no good reasons still
having it.

Key things this PR do:

1, remove the gp_libpq_fe directory.
2, build libpq source codes into two versions, for frontend and backend,
check the macro FRONTEND.
3, libpq for backend still bypasses local authentication, SSL and some
environment variables, and these are the whole differences.
Signed-off-by: NAdam Lee <ali@pivotal.io>

This guide is based on the centos-gpdb-dev docker images that Concourse uses, thus there are less things we need to add on top.
Signed-off-by: NAmil Khanzada <akhanzada@pivotal.io>

The installcheck-world target requires gssapi, so add it to default configuration
Signed-off-by: NGoutam Tadi <gtadi@pivotal.io>

- Open Source GPDB compile
- No ORCA yet -- getting there soon

[#151180202]
Signed-off-by: NGoutam Tadi <gtadi@pivotal.io>

* Enable PXF by default for GPDB builds

* Disable pxf wherever libcurl is disabled

- instead of trying to keep GPDB readme in sync with GPORCA readme, just refer to it

- fixes cd path
- removes macOS warning that is not currently an issue
- treats comment like other readme comments

- Move Conan instructions above manual orca setup instructions
  so that people don't do manual work first (like we did).
- Inline recommendation to parallelize make with -j8.
- Fix formatting of code blocks in README.md

See issues:
 - https://github.com/greenplum-db/gpdb/issues/3178
 - https://github.com/greenplum-db/gpdb/pull/3332

* Use built-in JSON parser for PXF fragments

Instead of relying on a external library, use the built-in JSON
parser in the backend for the PXF fragments parsing. Since this
replaces the current implementation with an event-based callback
parser, the code is more complicated, but dogfooding the parser
that we want extension writers to use is a good thing.

This removes the dependency on json-c from autoconf, and enables
building PXF on Travis for extra coverage.

* Use elog for internal errors, and ereport for user errors

Internal errors where we are interested in source filename should
use elog() which will decorate the error messages automatically
with this information. The connection error is interesting for the
user however, use ereport() instead there.

Add required steps before building GPDB on centos.
Fixes issue #2715, #2995 and #3163.

[ci skip]

The README was still referencing gp-xerces even though it's no
longer required for ORCA, so this was removed. On top of that,
some Markdown formatting fixes, minor wordsmithing, typo fixes
as well as some whitespace cleanup and turned URLs into links.

This makes the linux directions look more like the macOS directions for the top level readme.

* README updates for PXF setup instructions

* PXF README updates for PXF setup instructions

* test update

* README updates for PXF setup instructions

* PXF README updates for PXF setup instructions

* note on curl depedancy

* minor update

* Change the directory location and update readme

When conan is used to build the dependencies (orca & xerces) of gpdb, it
copies the headers and libraries to the path specified in
the imports section of the conanfile.txt.
Changing the target copy location to /usr/local/include and
/usr/local/lib as its the default for gpdb. In case the user
prefers to have a different directory, they can change the location
accordingly.

Signed-off-by: NJohn Gaskin <johntgaskin@gmail.com>
Signed-off-by: NTodd Sedano <tsedano@pivotal.io>

- Currently the readme leaves out the  dependency
- Places all dependencies into one location in the readme

- make distclean can not be called before configure

Signed-off-by: NChris Hajas <chajas@pivotal.io>

Partially addresses https://github.com/greenplum-db/gpdb/issues/2422Signed-off-by: NTodd Sedano <professor@gmail.com>
Signed-off-by: NChris Hajas <chajas@pivotal.io>