Fix example for day and hours interval subtraction for new computation
method.
Update interval examples to display zero seconds, which is our default.
Backpatch to 8.1.X.
Per my recent proposal. I ended up basing the implementation on the
existing mechanism for enforcing valid join orders of IN joins --- the
rules for valid outer-join orders are somewhat similar.
< * Allow star join optimizations
<
< While our bitmap scan allows multiple indexes to be joined to get
< to heap rows, a star joins allows multiple dimension _tables_ to
< be joined to index into a larger main fact table. The join is
< usually performed by either creating a cartesian product of all
< the dimmension tables and doing a single join on that product or
< using subselects to create bitmaps of each dimmension table match
< and merge the bitmaps to perform the join on the fact table. Some
< of these algorithms might be patented.
< * Flush cached query plans when the dependent objects change or
< when the cardinality of parameters changes dramatically
> * Flush cached query plans when the dependent objects change,
> when the cardinality of parameters changes dramatically, or
> when new ANALYZE statistics are available
Drake:
< and merge the bitmaps to perform the join on the fact table.
> and merge the bitmaps to perform the join on the fact table. Some
> of these algorithms might be patented.
* Allow star join optimizations
While our bitmap scan allows multiple indexes to be joined to get
to heap rows, a star joins allows multiple dimension _tables_ to
be joined to index into a larger main fact table. The join is
usually performed by either creating a cartesian product of all
the dimmension tables and doing a single join on that product or
using subselects to create bitmaps of each dimmension table match
and merge the bitmaps to perform the join on the fact table.
< * Flush cached query plans when the dependent objects change
> * Flush cached query plans when the dependent objects change or
> when the cardinality of parameters changes dramatically
< * %Allow pooled connections to list all prepared queries
> * %Allow pooled connections to list all prepared statements
28c28
< the queries prepared in the current session.
> the statements prepared in the current session.
143c143
< o Allow a warm standby system to also allow read-only queries
> o Allow a warm standby system to also allow read-only statements
404c404
< * Add GUC to issue notice about queries that use unjoined tables
> * Add GUC to issue notice about statements that use unjoined tables
490c490
< Another idea would be to allow actual SELECT queries in a COPY.
> Another idea would be to allow actual SELECT statements in a COPY.
554c554
< o Allow function argument names to be queries from PL/PgSQL
> o Allow function argument names to be statements from PL/PgSQL
591c591
< o Improve psql's handling of multi-line queries
> o Improve psql's handling of multi-line statements
< Currently, while \e saves a single query as one entry, interactive
< queries are saved one line at a time. Ideally all queries
> Currently, while \e saves a single statement as one entry, interactive
> statements are saved one line at a time. Ideally all statements
665c665
< o Allow query results to be automatically batched to the client
> o Allow statement results to be automatically batched to the client
667c667
< Currently, all query results are transfered to the libpq
> Currently, all statement results are transfered to the libpq
672c672
< One complexity is that a query like SELECT 1/col could error
> One complexity is that a statement like SELECT 1/col could error
739c739
< * Allow queries across databases or servers with transaction
> * Allow statements across databases or servers with transaction
< inheritance, allow it to work for UPDATE and DELETE queries, and allow
< it to be used for all queries with little performance impact
> inheritance, allow it to work for UPDATE and DELETE statements, and allow
> it to be used for all statements with little performance impact
876c876
< * Consider automatic caching of queries at various levels:
> * Consider automatic caching of statements at various levels:
947c947
< a single session using multiple threads to execute a query faster.
> a single session using multiple threads to execute a statement faster.
1025c1025
< * Log queries where the optimizer row estimates were dramatically
> * Log statements where the optimizer row estimates were dramatically
1146c1146
< of result sets using new query protocol
> of result sets using new statement protocol
DROP CONSTRAINT
This form drops constraints on a table. Currently, constraints on tables
are not required to have unique names, so there may be more than one
constraint matching the specified name. All matching constraints will be
dropped.
To my knowledge, it is no longer possible to create constraints with the
same name for the same relation. When you create a constraint and specify
the same name explictly, an error is raised. Implicit constraint creation
won't choose an existing name either and up to now you could not rename a
constraint. Renaming works with the patch I sent in a few hours ago but this
patch as well won't allow constraints with identical names on the same
relation.
The attached patch thus removes the note in the docs.
Joachim Wieland
