I'm composing a comparison table of database capabilities of several
different products. I've been reading the DB2 for AS/400 documentation
(dated year 2000) and have gathered many of the information I needed
(of course this is for an old version of DB2). could someone confirm
or complete the points below, specifically in relation to the current
releases of the product.
* DB2 cannot index binary data (BLOB/CLOB).
* ALTER TABLE can't rename column name/index name/constraint name.
* DB2 doesn't support functional index (index on expression/function).
* Maximum number of indexes per table?
* SEQUENCE (as in PostgreSQL) is not supported, but anyway SEQUENCE
can be implemented using a 'counter table'.
* Regexp is not recognized, only standard SQL LIKE pattern.
* Maximum number of schemas per database?
* There is no built-in BOOLEAN data type, but one can use SMALLINT or
CHAR(1) + CHECK constraint.
* Does DB2 use a generational/MVCC/record-versioning architecture, to
allow writers to not block readers and vice versa?
* Several user-defined functions can be created with the same name but
with different signatures (argument type). For example,
REVERSE(varchar ) and REVERSE(blob).
* Does DB2 have/use WAL (write-ahead logs)?
* Maximum size of BLOB/CLOB is still around 15MB.
* Maximum length of identifier for column names is still 28
characters.
* Does DB2 support nested transaction/savepoint?
different products. I've been reading the DB2 for AS/400 documentation
(dated year 2000) and have gathered many of the information I needed
(of course this is for an old version of DB2). could someone confirm
or complete the points below, specifically in relation to the current
releases of the product.
* DB2 cannot index binary data (BLOB/CLOB).
* ALTER TABLE can't rename column name/index name/constraint name.
* DB2 doesn't support functional index (index on expression/function).
* Maximum number of indexes per table?
* SEQUENCE (as in PostgreSQL) is not supported, but anyway SEQUENCE
can be implemented using a 'counter table'.
* Regexp is not recognized, only standard SQL LIKE pattern.
* Maximum number of schemas per database?
* There is no built-in BOOLEAN data type, but one can use SMALLINT or
CHAR(1) + CHECK constraint.
* Does DB2 use a generational/MVCC/record-versioning architecture, to
allow writers to not block readers and vice versa?
* Several user-defined functions can be created with the same name but
with different signatures (argument type). For example,
REVERSE(varchar ) and REVERSE(blob).
* Does DB2 have/use WAL (write-ahead logs)?
* Maximum size of BLOB/CLOB is still around 15MB.
* Maximum length of identifier for column names is still 28
characters.
* Does DB2 support nested transaction/savepoint?
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