Here is the second version of the proposal. It's taken into account all
agreements we made during discussion and we'll do it in this way if there
are no objections.
================PROPOSAL======================
GOALS
======
1) Extend the current limits on database size
2) Keep non active parts of a database on slow disks (having big volume)
3) Split indices from the database
etc
SYNTAX
=======
Note: *MAIN* - is a name of the basic database file.
1. *CREATE TABLESPACE <TS NAME> FILE '/path/to/file'*
2. *ALTER TABLESPACE <TS NAME> FILE '/path/to/file'*
FILE can contain either an absolute path or a relative to the main database
file.
3. *DROP TABLESPACE <TS NAME> [INCLUDING CONTENTS]*
If the tablespace contains some database objects the behaviour depends
on INCLUDING CONTENTS clause. if it is specified all database objects
in the tablespace will be dropped as well. Otherwise there will be an
error.
4. CREATE TABLE ...
(
...
FIELD TYPE CONSTRAINT ... USING INDEX ... *TABLESPACE {<TS NAME> | MAIN}*
-- field constraint tablespace
...
CONSTRAINT ... USING INDEX ... *TABLESPACE {<TS NAME> | MAIN}* -- table
constraint tablespace
...
)
*TABLESPACE <TS NAME>*
if the tablespace name is not specified *MAIN* will be used as default
tablespace for the table data.
A constraint will use the tablespace of the table if *TABLESPACE* is
omitted.
5. ALTER TABLE <TABLE NAME> *ALTER TABLESPACE {<TS NAME> | MAIN}*
Data of the table will be moved to the specified tablespace or the main
database.
6. CREATE INDEX … *TABLESPACE {<TS NAME> | MAIN}*
The index will be created in the specified tablespace or the main database.
If tablespace is omitted the index will be created in the tablespace of the
table.
7. ALTER INDEX <INDEX NAME>* ALTER TABLESPACE {<TS NAME> | MAIN}*
Data of the index will be moved to the specified tablespace or the main
database.
ODS CHANGES
=============
A new table RDB$TABLESPACES:
RDB$TABLESPACE_ID - SMALLINT
RDB$TABLESPACE_NAME - CHAR (63)
RDB$SECURITY_CLASS - CHAR (63)
RDB$DESCRIPTION - BLOB SUBTYPE TEXT SEGMENT SIZE 80
RDB$OWNER_NAME - CHAR (63)
RDB$FILE_NAME - VARCHAR (255)
A new field in RDB$INDICES:
RDB$TABLESPACE_NAME - CHAR (63)
A new field in RDB$RELATION_FIELDS:
RDB$TABLESPACE_NAME - CHAR (63)
New fields in RDB$RELATIONS:
RDB$TABLESPACE_NAME - CHAR (63)
RDB$POINTER_PAGE - INTEGER
RDB$ROOT_PAGE - INTEGER
Add page space id to page number in ods.h:index_root_page.
UTILITIES
========
Logical backup
--------------------
gbak -b works as usual for now. It gets data from a database
transparently working with tablespaces.
Logical restore
--------------------
gbak -c -TABLESPACE_MAP(PING_FILE) /path/to/file/map/tablespaces
The option TABLESPACE_MAP(PING_FILE) specifies a path to the file
which maps tablespace names on file names. For example,
TS1 /path/to/tablespace1
TS2 /path/to/tablespace2
or directly in the command line
gbak -c -ts <TSNAME1>=/path/to/tablespace1 -ts <TSNAME2>=...
It allows you to restore tablespace contents to new places.
If the option is not specified gbak will use old locations for every
tablespace.
The initial implementation requires explicitly specifying all tablespace
files. Later we can add merging tablespaces or default original paths.
SOME DETAILS
=============
pag_header in every tablespace is reserved and may be replaced by a
new page type.
pag_scns and pag_pip are located in every tablespace
pag_root is located in the tablespace where a table is located
It's possible to create up to 253 tablespaces.
nbackup support is postponed.
Location of BLOB fields is postponed.
Page size is identical for every tablespace and the main database.
==================END=========================
--
Roman Simakov
Firebird-Devel mailing list, web interface at
https://lists.sourceforge.net/lists/listinfo/firebird-devel
