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Sybase Hints

CATEGORY HINT 12.5 15.0 Info Status
Logical distinct   No explicit implementation
no
Physical distinct_sorted   Only for SELECT statements containing DISTINCT and only for tables
yes
Physical distinct_sorting   Only for SELECT statements containing DISTINCT and only for tables yes
Physical distinct_hashing   Only for SELECT statements containing DISTINCT and only for tables yes
Logical group   No explicit implementation no
Physical group_sorted   Only for SELECT statements from tables (not working for views) with no having and no order by clause yes
Physical group_hashing   Only for SELECT statements from tables (not working for views) with no having and no order by clause
Physical group_inserting   Not implemented - The group_inserting operator describes the way that ASE 15 handles a group by statement when a table is clustered. I don't think this can be forced via the plan statement. I don't think it is worth implementing this hint even if it is possible. Harry Hellal - sybase specialist no
Logical g_join   No explicit implementation no

nl_g_join   Not applicable for: statements with chained queries; select statements with group by clause and having clause or group by clause and order by clause yes

m_g_join   Not applicable for: statements with chained queries; select statements with group by clause and having clause or group by clause and order by clause yes
Logical join   No explicit implementation no

nl_join   Not applicable for: select statements with group by clause and having clause or group by clause and order by clause yes

m_join   Not applicable for: select statements with group by clause and having clause or group by clause and order by clause yes

h_join   Not applicable for: select statements with group by clause and having clause or group by clause and order by clause yes
Logical union No explicit implementation. no
Physical append_union_all   Not applicable for: UNION chained clauses, nested sub-selects in a from clause, if a group by clause is present or if scalar aggregation is present. yes
Physical merge_union_all   Not applicable for: UNION ALL chained clauses, nested sub-selects in a from clause or if a group by clause is present.
Physical merge_union_distinct   Not applicable for: UNION ALL chained clauses, nested sub-selects in a from clause or if a group by clause is present. yes
Physical hash_union_distinct   Not applicable for: UNION ALL chained clauses, nested sub-selects in a from clause, if a group by clause is present or if scalar aggregation is present. yes
Logical scan No explicit implementation. no
Physical i_scan Applied to all the table references in the from clause of the main select and of the sub select statements except: 1. statement has sub-selects 2. table reference has no indexes. yes
Physical t_scan Applied to all the table references in the from clause of the main select and of the sub select statements except: on Sybase 12.5 not applied for tables in the main query if : 1.statement has chained queries 2. Sub queries have group by and having clauses; and not applied to the tables in sub selects if: 1.has select statements in from clause of the main select, 2.sub queries have group by and having clauses 3.statement has select statements in select clause 4. statement has parent statement an insert statement; on Sybase 15 not applied for tables in sub selects : 1. has select statements in from clause of the main select 2.statement has chained queries. yes
Physical m_scan   Applied for all the tables if in the where clause there is a condition like: table1.indexedColumn1 condition body OR table1.indexedColumn2 condition body; Not applied if the "LIKE" operator is used. For columns that belong to a primary key only the first column is considered. yes

store No reasonable usages were found

Physical store_index   There isn't much value in implementing this operator.
Physical sort   Only for SELECT statements containing ORDER BY and only for tables
Filter nested Only used in combination with other operators. It does not change the execution plan by itself.
Physical xchg   Specify on-the-fly partitioning of a derived table.

Logical scalar_agg   Only used in combination with other operators. It does not change the execution plan by itself.


sequence   Is a keyword that will be used in the implementation of scalar_agg operator

hints We don't support combination of hints at this stage

prop Uses a set of pre-defined values.


table Used  only in combination with  others operators, when referring tables from subqueries

work_t This operator is applicable only together with store operator.

in Used  only in combination with  others operators, when referring tables from subqueries

subq Used  only in combination with  others operators, when referring tables from subqueries






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