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Code Issues

Minor fixes.

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robocop 2005-01-25 06:24:30 +00:00
parent 2b340ebb23
commit 607816519d
2 changed files with 5 additions and 5 deletions
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8
doc/sql.extensions/README.plan
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@ -14,11 +14,11 @@ PLAN clause
<indexed_retrieval> ::= <stream_alias> INDEX ( <index_name> [, <index_name> ...] ) <indexed_retrieval> ::= <stream_alias> INDEX ( <index_name> [, <index_name> ...] )
<navigational_scan> ::= <stream_alias> ORDER <index_name> [ INDEX ( <index_name> [, <index_name> ...] ) ] <navigational_scan> ::= <stream_alias> ORDER <index_name> [ INDEX ( <index_name> [, <index_name> ...] ) ]
<sorted_streams> ::= SORT ( <stream_retrieval> )
<joined_streams> ::= JOIN ( <stream_retrieval>, <stream_retrieval> [, <stream_retrieval> ...] ) <joined_streams> ::= JOIN ( <stream_retrieval>, <stream_retrieval> [, <stream_retrieval> ...] )
| [SORT] MERGE ( <sorted_streams>, <sorted_streams> ) | [SORT] MERGE ( <sorted_streams>, <sorted_streams> )
<sorted_streams> ::= SORT ( <stream_retrieval> )
Description: Description:
Natural scan means that all rows are fetched in their natural storage order, Natural scan means that all rows are fetched in their natural storage order,
which requires to read all pages and validate any search criteria afterward. which requires to read all pages and validate any search criteria afterward.
@ -37,6 +37,8 @@ PLAN clause
Then a data page is read and required row is fetched. Note that navigational scan produces Then a data page is read and required row is fetched. Note that navigational scan produces
random page I/O as reads are not optimized. random page I/O as reads are not optimized.
A sort operation performs an external sort of the given stream retrieval.
A join can be performed either via the nested loops algorithm (JOIN plan) or via A join can be performed either via the nested loops algorithm (JOIN plan) or via
the sort merge algorithm (MERGE plan). An inner nested loop join may contain as many the sort merge algorithm (MERGE plan). An inner nested loop join may contain as many
streams as required to be joined (as all of them are equivalent), whilst an outer streams as required to be joined (as all of them are equivalent), whilst an outer
@ -44,8 +46,6 @@ PLAN clause
nested JOIN clauses in the case of 3 or more outer streams joined. A sort merge operates nested JOIN clauses in the case of 3 or more outer streams joined. A sort merge operates
with two input streams which are sorted beforehand, then they're merged in a single run. with two input streams which are sorted beforehand, then they're merged in a single run.
A sort operation performs an external sort of the given stream retrieval.
Example(s): Example(s):
SELECT RDB$RELATION_NAME SELECT RDB$RELATION_NAME
FROM RDB$RELATIONS FROM RDB$RELATIONS

2
doc/sql.extensions/README.sequence_generators
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@ -11,7 +11,7 @@ Sequence generators
CREATE { SEQUENCE | GENERATOR } <name> CREATE { SEQUENCE | GENERATOR } <name>
DROP { SEQUENCE | GENERATOR } <name> DROP { SEQUENCE | GENERATOR } <name>
SET GENERATOR <name> TO <start_value> SET GENERATOR <name> TO <start_value>
ALTER SEQUENCE RESTART WITH <start_value> ALTER SEQUENCE <name> RESTART WITH <start_value>
GEN_ID (<name>, <increment_value>) GEN_ID (<name>, <increment_value>)
NEXT VALUE FOR <name> NEXT VALUE FOR <name>