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[TRAFODION-2351] Bulk load with log error rows enhancements

LOAD with log error rows failed when ERRORCOUNTER hbase table already exists.

LOAD command now returns the number of error rows skipped.

LOAD with truncate option dumps core when encounters an error.

Similar issue exist with PURGEDATA command too.

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Merge remote branch 'origin/master' into empty_lob_work

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Changes to support new syntax and implementation empty_blob/empty_clob for insert/updates Changes to support new syntax for updating a lob directly through a lobhandle without scanning the table.This is done via new ExeUtil operator. Changes to add columnname info to LOBMD_ table. This helps in mapping any given lobhandle back to the table and the column. Added new sections to the regression test executor/TEST130 to test these changes

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Merge [TRAFODION-2351] PR 876 Bulk load with log error rows enhancements

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TRAFODION-1586 Add support for external Traf tables mappedd to HBase tables

This is the initial support for HBase mapped tables.

A doc for external manuals will be added later.

regress/seabase/TEST022 contains various testcases.

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[TRAFODION-2351] Bulk load with log error rows enhancements

The LOAD command now outputs as follows:

Load with log error rows into selva.customer select * from hive.hive.customer ;


Task: CLEANUP Status: Started Time: 2016-12-11 00:54:37.642

Task: CLEANUP Status: Ended Time: 2016-12-11 00:54:37.672

Task: CLEANUP Status: Ended Elapsed Time: 00:00:00.030

Logging Location: /bulkload/logs/ERR_TRAFODION.SELVA.CUSTOMER_20161211_005437

Task: LOADING DATA Status: Started Time: 2016-12-11 00:54:37.672

Rows Processed: 99997

Task: LOADING DATA Status: Ended Time: 2016-12-11 00:54:58.296

Task: LOADING DATA Status: Ended Elapsed Time: 00:00:20.624

Task: COMPLETION Status: Started Time: 2016-12-11 00:54:58.296

Task: COMPLETION Status: Ended Time: 2016-12-11 00:54:59.521

Task: COMPLETION Status: Ended Elapsed Time: 00:00:00.756

In addition, currently the "LOADING DATA" task status is shown as it happens. In future,

the task status will be shown as it happens for all tasks.

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Merge [TRAFODION-2365] PR 850 HBase snapshot concept needs to be contained within HBaseClinet in Trafodion

[Trafodion 2351] HBase snapshot concept needs to be contained within HBaseClient in Trafodion

Moved snapshot creation/deletion from SequenceFileWriter to HBaseClient.

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[TRAFODION-2356] HBase snapshot concept needs to be contained within HBaseClient in Trafodion

Moved snapshot creation/deletion from SequenceFileWriter to HBaseClient.

  1. … 13 more files in changeset.
TRAFODION-2363 Add support to return hive MD info in relational format

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[TRAFODION-2317] Infrastructure for common subexpressions

This is a first set of changes to allow us to make use of CTEs

(Common Table Expressions) declared in WITH clauses and to create

a temp table for them that is then read multiple times in the query.

This also includes a fix for

[TRAFODION-2280] Need to remove salt columns from uniqueness constraints

Summary of changes:

- Adding a unique statement number in CmpContext

- Moving the execHiveSQL method from the OSIM code to CmpContext

- Adding a list of common subexpressions and their references

to CmpStatement

- Adding the ability to the Hive Truncate operator to drop the

table when the TCB gets deallocated

- Adding the ability to the HDFS scan to compute scan ranges at

runtime. Those are usually determined in the compiler. This is

only supported for simple, non-partitioned, delimited tables.

We need this because we populate the temp table and read from

in in the same statement, without the option of compiling

after we inserted into the temp table.

- Special handling in the MapValueIds node of common subexpressions.

See the comment in MapValueId::preCodeGen().

- Moved the binder code to create a FastExtract node into a new

method FastExtract::makeFastExtractTree(), to be able to call

it from another place.

- MapValueIds no longer looks at the "used by MVQR flag" to determine

the method for VEGRewrite. Instead it checks whether a list of

values has been provided to do this.

- Adding a new method, RelExpr::prepareMeForCSESharing, that is

kind of an "unnormalizer", undoing some of the normalizer


- Implementing the steps for common subexpression materializations

described below.

- Adding the ability to suppress the Hive timestamp modification

check when truncating a Hive table

- Adding an optimizer rule to eliminate CommonSubExprRef nodes.

These nodes should not normally survive past the SQO phase, but

if the SQO phase gets interrupted by an exception, that could

happen, since we then fall back to a copy of the tree before

SQO. In the future, we can consider cost-based decision on

what to do with common subexpressions.

- Adding CommonSubExprRef nodes in the parser whenever we expand

a CTE reference.

- Adding cleanup code to the "cleanup obsolete volatile tables"

command that removes obsolete Hive tables used for common


Other changes contained in this change set:

- Optimization for empty scans, like select * from t where 1=0

This now generates a cardinality constraint with 0 rows, which

can be used later to eliminate parts of a tree.

(file OptLogRelExpr.cpp)

- [TRAFODION-2280] Need to remove salt columns from uniqueness

constraints generated on salted tables.

(file OptLogRelExpr.cpp)

- Got rid of the now meaningless "seamonster" display in EXPLAIN.

(file GenExplain.cpp and misc. expected files)

- Suppress display of "zombies" in the cstat command. Otherwise,

these zombies (marked as <defunct>) prevent Trafodion from

starting, because they are incorrectly considered "orphan"

processes. This could require a reboot when no reboot is necessary.

(file core/sqf/sql/scripts/pstat)

Incomplete list of things left to be done:

- TRAFODION-2316: Hive temp tables are not secure. Use volatile

tables instead.

- TRAFODION-2315: Add heuristics to decide when to use the temp table


- TRAFODION-2320: Make subquery unnesting work with common subexpressions.

Generated Plans


The resulting query plan for a query Q with n common

subexpressions CSE1 ... CSEn looks like this:






/ \

Union Q

/ \

... CTn



/ \


Each of the CTi variables looks like the following, an



/ \

Truncate FastExtract TEMPi



The original query Q has the common subexpressions replaced

with the following:



scan TEMPi

Here is a simple query and its explain:

prepare s from

with cse1 as (select d_date_sk, d_date, d_year, d_dow, d_moy from date_dim)

select x.d_year, y.d_date

from cse1 x join cse1 y on x.d_date_sk = y.d_date_sk

where x.d_moy = 3;

>>explain options 'f' s;


---- ---- ---- -------------------- -------- -------------------- ---------

11 . 12 root 1.46E+005

5 10 11 blocked_union 1.46E+005

7 9 10 merge_join 7.30E+004

8 . 9 sort 1.00E+002

. . 8 hive_scan CSE_TEMP_CSE1_MXID11 1.00E+002

6 . 7 sort 5.00E+001

. . 6 hive_scan CSE_TEMP_CSE1_MXID11 5.00E+001

1 4 5 blocked_union 7.30E+004

2 . 4 hive_insert CSE_TEMP_CSE1_MXID11 7.30E+004

. . 2 hive_scan DATE_DIM 7.30E+004

. . 1 hive_truncate 1.00E+000

--- SQL operation complete.


CQDs to control common subexpressions


CSE_FOR_WITH is the master switch.

CQD Value Default Behavior

--------------------- --------- ------- ---------------------------------------


ON Insert a CommonSubExprRef node in the

tree whenever we reference a CTE

(table defined in a WITH clause)

CSE_USE_TEMP OFF Y Disable creation of temp tables

for common subexpressions

SYSTEM Same as OFF for now

ON Always create a temp table for

common subexpressions where possible


ON Emit diagnostic warnings that show why

we didn't create temp tables for

common subexpressions


ON Cleanup Hive tables used for CSEs with

the "cleanup obsolete volatile tables"


CommonSubExprRef relational operators


This is a new RelExpr class that is introduced. It marks the common

subexpressions in a RelExpr tree. This operator remembers the name of

a common subexpression (e.g. the name used in the WITH clause).

Multiple such operators can reference to the same name. Each of

these references has a copy of the tree.

Right now, these operators are created in the parser when we expand a

CTE (Common Table Expression), declared in a WITH clause. If the CTE

is referenced only once, then the CommonSubExprRef operator is removed

in the binder - it also doesn't live up to its name in this case.

The remaining CommonSubExprRef operators keep track of various changes

to their child trees, during the binder and normalizer phases. In

particular, it tracks which predicates are pushed down into the child

tree and which outputs are eliminated.

The CmpStatement object keeps a global list of all the

CommonSubExprRef operators in a statement, so the individual operators

have a way to communicate with their siblings:

- A statement can have zero or more named common subexpressions.

- Each reference to a common subexpression is marked in the RelExpr

tree with a CommonSubExprRef node.

- In the binder and normalizer, common subexpressions are expanded,

meaning that multiple copies of them exist, one copy per


- Common subexpressions can reference other common subexpressions,

so they, together with the main query, for a DAG (directed

acyclic graph) of dependencies.

- Note that CTEs declared in a WITH clause but not referenced are

ignored and are not part of the query tree.

In the semantic query optimization phase (SQO), the current code makes

a heuristic decision what to do with common subexpressions - to

evaluate them multiple times (expand) or to create a temporary table

once and read that table multiple times.

If we decide to expand, the action is simple: Remove the

CommonSubExprRef operator from the tree and replace it with its child.

If we decide to create a temp table, things become much more difficult.

We need to do several steps:

- Pick one of the child trees of the CommonSubExprRefs as the one to


- Undo any normalization steps that aren't compatible with the other

CommonSubExprRefs. That means pulling out predicates that are not

common among the references and adding back outputs that are

required by other references. If that process fails, we fall back

and expand the expressions.

- Create a temp table tmp.

- Prepare an INSERT OVERWRITE TABLE tmp SELECT * FROM cse tree

that materializes the common subexpression in a table.

- Replace the CommonSubExprRef nodes with scans of the temp table.

- Hook up the insert query tree with the main query, such that it

is executed before the main query starts.

Temporary tables


At this time, temporary tables are created as Hive tables, with a

fabricated, unique name, including the session id, a unique statement

number within the session, and a unique identifier of the common

subexpression within the statement. The temporary table is created at

compile time. The query plan contains an operator to truncate the

table before populating it. The "temporary" Hive table is dropped when

the executor TCB is deallocated.

Several issues are remaining with this approach:

- If the process exits before executing and deallocating the statement,

the Hive table is not cleaned up.

Solution (TBD): Clean up these tables like we clean up left-over

volatile tables. Both are identified by the session id.

- If the executor runs into memory pressure and deallocates the TCB,

then allocates it again at a later time, the temp table is no longer


Solution (TBD): Use AQR to recompile the query and create a new table.

- Query cache: If we cache a query, multiple queries may end up with

the same temporary table. This works ok as long as these queries are

executed serially, but it fails if both queries are executed at the

same time (e.g. open two cursors and fetch from both, alternating).

Solution (TBD): Add a CQD that disables caching queries with temp tables

for common subexpressions.

In the future we also want to support volatile tables. However, those also

have issues:

- Volatile tables aren't cleaned up until the session ends. If we run

many statements with common subexpressions, that is undesirable. So,

we have a similar cleanup problem as with Hive tables.

- Volatile tables take a relatively long time to create.

- Insert and scan rates on volatile Trafodion tables are slower than

those on Hive tables.

To-do items are marked with "Todo: CSE: " in the code.

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[JIRA TRAFODION-2141] Cluster view of hbase stats

-- added column REGION_SERVER to region stats virtual table

-- added cluster view of hbase stats

Syntax: select * from table(cluster stats());

-- added support for 'where' pred in stats queries

Syntax: select * from table(cluster stats()) where schema_name = 'SCH';

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Merge remote branch 'origin/master' into lobglobals_fix




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Changes to move hdfFs handing to the context globals level and remove all disconnects from hdfs from the various components.

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JIRA TRAFODION-2022 Some more changes related to hive truncate

-- support for 'TRUNCATE' command for hive tables

-- support for truncate with PARTITION specification

-- separation of traf purgedata and hive truncate code into

different classes and tdbs

-- some cleanup of obsolete older purgedata code

-- new tests added to regress/hive/TEST005

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Merge remote branch 'origin/pr/507/head' into merge_507

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hive data modification detection: commit #4

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Support for external lobs. Data files are stored externally in HDFS and only filehandles and file locations are stored in internal Trafodion tables.

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[TRAFODION-1955] JNI optimization at the time of compilation

Removed ByteArrayList class and used array of byte array instead.

Only one JNI to java transistion is done to getRegionStartKeys

and getRegionEndKeys at the time of query compilation

Also fixed an issue with lib_mgmt Makefile.

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Various fixes (details below)

-- ddl_transactions cqd is now on by default.

All ddl, where allowed and supported, will run

within one transaction

-- drop schema has been disabled to run within one transaction.

When jira 1948 is fixed, it will be enabled.

-- hdfs scan handles hive col values > 32K

-- pcode handles varchar with len > 32K

-- errors (gaps, unsorted order) for cqd values in nadefaults are

detected without crashing arkcmp.

-- volatile and regular schema drop returns the reason if an error occured

(for ex: name of objects that could not be dropped)

-- dateformat displays european format correctly with a blank

seperator between date and time values

-- dateformat timestamp in usa format displayes time with AM/PM

-- dateformat inside a cast function returns correct values.

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support for get command for LOB tables. Support for tracing LOB operations.

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JIRA TRAFODION-1798 (ddl xns) and few other fixes, details below.

-- support for sql part of ddl xns. Section 1 of JIRA TRAFODION-1798

-- cqd ddl_transactions to enable or disable ddl xns.

Default is currently off. Once it is tested, it will be turned on.

Dev regressions are run with cqd set to ON

-- get stmts run with read committed to get changes in current xns

-- support for where preds with get stmts

-- scan to pass in transid even if running with read uncommitted access.

This enables rows modified in current xn to be returned.

-- cleanup no longer return multiple duplicate error messages if

objects id is not found.

-- cleanup no longer includes internallay created schemas (_HV_ , _HB_)

during cleanup operations.

-- Correct error msg was not getting returned if an invalid index

existed in table and the same index was created again.

-- init traf, drop md views was giving an error if views didnt exist.

That has been fixed.

-- regressions with -diff option now show original file timestamps

instead of the timestamp when the diff command was run.

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Merge remote branch 'origin/master' into lob_work_buffer




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Recommitting the last commit. Some files did notget added. Context/changes are the same as earlier commit.

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JIRA Trafodion-1645 SQL commands to retrieve region stats.

Details in JIRA.

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Merge remote branch 'origin/master' into lob_work_files2

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Fixes for extract to files and dealing with issues ith 2 or more lob columns.

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Part 2 of changes to update license text in Trafodion source

This check-in updates license text in all source files in the

core/sql directory. Remaining directories will be done in

later check-ins.

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Support for chunking during insertion into lobs and extracting into external files. Currently supported for lob insert and lob extract to/from local linux files.

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Merge remote branch 'core/master'

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