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https://issues.apache.org/jira/browse/TRAFODION-1462?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14715271#comment-14715271
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Suresh Subbiah commented on TRAFODION-1462:
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This changed was merged today with this commit.
https://github.com/apache/incubator-trafodion/commit/5928f31a1e20c70a528101487def3db0ef0ade9c
This commit addresses multiple JIRAs. The actual change for this JIRA is in
nadefaults.cpp
> Enable HBase serialization by default
> -------------------------------------
>
> Key: TRAFODION-1462
> URL: https://issues.apache.org/jira/browse/TRAFODION-1462
> Project: Apache Trafodion
> Issue Type: Improvement
> Components: sql-general
> Affects Versions: 1.0 (pre-incubation)
> Reporter: Suresh Subbiah
> Assignee: Suresh Subbiah
> Fix For: 2.0-incubating
>
> Original Estimate: 168h
> Remaining Estimate: 168h
>
> Currently when a Trafodion table is created, by default data stored in HBase
> tables is not serialized (i.e. not encoded or stored in a form that will
> allow evaluation of range predicates with HBase Filters executing in the
> RegionServer proceses). Trafodion did support storing Trafodion data in such
> an encoded format, but the feature had to be explicitly enabled with
> cqd HBASE_SERIALIZATION 'ON' ;
> With this change the default setting for the cqd has been changed to ON.
> Tables will now be created by default with columns having the serialized
> attribute. This can be verified by using the showddl command. For example
> >>showddl customer_demographics ;
> CREATE TABLE TRAFODION.SCH.CUSTOMER_DEMOGRAPHICS
> (
> CD_DEMO_SK INT NO DEFAULT NOT NULL NOT DROPPABLE
> SERIALIZED
> , CD_GENDER CHAR(1) CHARACTER SET ISO88591 COLLATE
> DEFAULT DEFAULT NULL SERIALIZED
> , CD_MARITAL_STATUS CHAR(1) CHARACTER SET ISO88591 COLLATE
> DEFAULT DEFAULT NULL SERIALIZED
> , CD_EDUCATION_STATUS CHAR(20) CHARACTER SET ISO88591 COLLATE
> DEFAULT DEFAULT NULL SERIALIZED
> , CD_PURCHASE_ESTIMATE INT DEFAULT NULL SERIALIZED
> , CD_CREDIT_RATING CHAR(10) CHARACTER SET ISO88591 COLLATE
> DEFAULT DEFAULT NULL SERIALIZED
> , CD_DEP_COUNT INT DEFAULT NULL SERIALIZED
> , CD_DEP_EMPLOYED_COUNT INT DEFAULT NULL SERIALIZED
> , CD_DEP_COLLEGE_COUNT INT DEFAULT NULL SERIALIZED
> )
> STORE BY (CD_DEMO_SK ASC)
> ;
> CREATE INDEX CD_DEP_COLLEGE_COUNT_IDX ON TRAFODION.SCH.CUSTOMER_DEMOGRAPHICS
> (
> CD_DEP_COLLEGE_COUNT ASC
> )
> ;
> CREATE INDEX CD_DEP_COUNT_IDX ON TRAFODION.SCH.CUSTOMER_DEMOGRAPHICS
> (
> CD_DEP_COUNT ASC
> )
> ;
> The create table statements used for this table is
> create table customer_demographics
> (
> cd_demo_sk int not null,
> cd_gender char(1),
> cd_marital_status char(1),
> cd_education_status char(20),
> cd_purchase_estimate int,
> cd_credit_rating char(10),
> cd_dep_count int,
> cd_dep_employed_count int,
> cd_dep_college_count int
> ) store by (cd_demo_sk);
> create index cd_dep_count_IDX on customer_demographics(cd_dep_count);
> create index cd_dep_college_count_IDX on
> customer_demographics(cd_dep_college_count);
> The indexes are also serialized though showddl does not show it.
> Having a column as serialized allows data to be stored in a format suitable
> for using HBase filters. However to get HBase filters in the execution plan
> for a SQL query, the cqd HBASE_FILTER_PREDS must be set to 'ON'. This cqd
> still defaults to 'OFF' as in some cases it is better to evaluate the
> predicate in the Trafodion/SQL layer, rather than the RegionServers (since
> Trafodion can use more ESPs to further parallelize predicate evaulation).
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