public static enum Constants.QueryHints extends java.lang.Enum<Constants.QueryHints>
Keys are case-sensitive and enumeration.name() method should be used for appropriate key strings.
| Modifier and Type | Class and Description |
|---|---|
static class |
Constants.QueryHints.SizerHints
SizerHint constant values which can be passed comma separated.
|
| Enum Constant and Description |
|---|
bulkFetch |
constraint
Query Hint to force usage of index enforcing a particular constraint.
|
executionEngine
Query hint to specify the execution engine for the query.
|
hashInitialCapacity |
hashLoadFactor |
hashMaxCapacity |
index
Query Hint to force usage of any particular index.
|
joinOrder
Query Hint to override optimizer's choice of ordering tables.
|
joinStrategy
To override default optimizer's choice of join strategy.
|
queryHDFS
Query hint to specify whether to query HDFS data.
|
sizerHints
Memory Analytics sizer query hints.
|
statementAlias
Query Hint to alias an user query that will be shown in Visual Statistics
Display (VSD) instead of system generated statement alias.
|
withSecondaries
Query Hint to indicate inclusion of secondary buckets of partitioned
tables while joining with virtual tables.
|
| Modifier and Type | Method and Description |
|---|---|
static Constants.QueryHints |
valueOf(java.lang.String name)
Returns the enum constant of this type with the specified name.
|
static Constants.QueryHints[] |
values()
Returns an array containing the constants of this enum type, in
the order they are declared.
|
public static final Constants.QueryHints joinStrategy
Possible values NESTEDLOOP or HASH
This can be FROM clause as well as table optimizer hint, in other words, this can be mentioned between FROM clause and the first table name or after each table name.
examples:
SELECT a, b FROM -- GEMFIREXD-PROPERTIES joinStrategy=HASH \n userTable1
t1, userTable2 t2 WHERE t1.col1 = t2.col1
SELECT a, b FROM userTable1
t1 -- GEMFIREXD-PROPERTIES joinStrategy=HASH \n, userTable2 t2 WHERE t1.col1 = t2.col1
public static final Constants.QueryHints joinOrder
joinStrategy.
Possible values are FIXED or UNFIXED, where FIXED will ensure ordering of the tables as appeared in the FROM list.
This can only be used with FROM clause, in other words, this can only be mentioned between FROM clause and the first table name.
example:
SELECT a, b FROM -- GEMFIREXD-PROPERTIES joinOrder=FIXED \n userTable1
t1, userTable2 t2 -- GEMFIREXD-PROPERTIES joinStrategy=HASH \n WHERE t1.col1 = t2.col1
public static final Constants.QueryHints index
Possible values are unqualified index name or NULL
indicating table scan.
This can only be used within TableExpression and only on base tables. Cannot be specified for views or derived tables.
public static final Constants.QueryHints constraint
index property but index is used via
constraint name.
Possible values are unqualified constraint name of primary key, foreign key or unique constraint.
This can only be used within TableExpression and only on base tables.
public static final Constants.QueryHints hashInitialCapacity
public static final Constants.QueryHints hashLoadFactor
public static final Constants.QueryHints hashMaxCapacity
public static final Constants.QueryHints bulkFetch
public static final Constants.QueryHints withSecondaries
If true, partitioned table's secondary bucket will be
considered for routing and scanning while performing the join with
virtual table output.
This can only be used on base tables or virtual tables.
example:
SELECT dsid(), count(1) from sys.members , userPartitionedTable t1
-- GEMFIREXD-PROPERTIES withSecondaries=true \n GROUP BY dsid()
Following query will return Entry Size/Value Size for primary buckets
only.
SELECT * FROM sys.memoryAnalytics -- GEMFIREXD-PROPERTIES withSecondaries=false \n
public static final Constants.QueryHints statementAlias
This can only be used in FROM clause i.e. immediately after the FROM clause and before the table name. WhiteSpace characters are not allowed as word separator.
example:
SELECT * FROM -- GEMFIREXD-PROPERTIES statementAlias=My_QUERY \n userTable t1
-- GEMFIREXD-PROPERTIES index=IDX_COL1 \n WHERE t1.col1 is not null
public static final Constants.QueryHints queryHDFS
Possible values are 'true' or 'false'.
This can only be used as a table optimizer hint i.e. can only be specified immediately after each table name.
example:
SELECT * FROM userTable t1 -- GEMFIREXD-PROPERTIES queryHDFS=true \n
WHERE t1.col1 is not null
public static final Constants.QueryHints executionEngine
Possible values are 'Spark' or 'Store'.
This can only be used with FROM clause, in other words, this can only be mentioned between FROM clause and the first table name.
example:
SELECT * FROM userTable t1 -- GEMFIREXD-PROPERTIES executionEngine=Spark \n
WHERE t1.col1 is not null
public static final Constants.QueryHints sizerHints
Constants.QueryHints.SizerHintspublic static Constants.QueryHints[] values()
for (Constants.QueryHints c : Constants.QueryHints.values()) System.out.println(c);
public static Constants.QueryHints valueOf(java.lang.String name)
name - the name of the enum constant to be returned.java.lang.IllegalArgumentException - if this enum type has no constant with the specified namejava.lang.NullPointerException - if the argument is nullCopyright © 2010-2015 Pivotal Software, Inc. All rights reserved.