On 19-Nov-2015 12:00 -0600, Rob wrote:
On 2015-11-19 11:48, CRPence wrote:
On 19-Nov-2015 11:15 -0600, Rob wrote:
Now since I am getting good with DB2 SQL...
And using the System i Navigator... according to IBM
Columns are grouped by Table
Tables are grouped by Schema
Schemas are contained within a Catalog
A "Catalog". Really? Where do they come with this stuff [and those
who would regurgitate such info]? Odd how much strange stuff that
is offered up by, or at least attributed to, the so-called "IBM".
IMNSHO, a response of "within a Directory", "within a Cabinet", or
"within a Senate" would have been just as accurate and meaningful,
with respect to the DB2 for IBM i ;-)
Open System I Navigator... choose your database... Run SQL Script
SELECT * FROM SYSIBM.TABLES
You get:
TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME....
SELECT * FROM SYSIBM.COLUMNS
You get:
TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, COLUMN_NAME...
Sure. But my point was that _from a DB2 for i perspective_, the term
CATALOG is almost meaningless, as contrasted with having said the
CURRENT SERVER [which is whence the data for TABLE_CATALOG is derived],
which is the local database connection, which is the Relational Database
(RDB) Directory Entry (RDBDIRE) for *LOCAL that defines the "Relational
database name".
I would expect that anyone trying to find information about the
"catalog" in the TABLE_CATALOG sense, within the documentation of the
DB2 for i SQL, will be hard-pressed to find anything that could explain
the origin of the term; nothing other than the column label of:
"Relational database name". Worse, such a person is likely to become
confused when searching the term, because predominantly the term
/catalog/ will be seen used to refer to the VIEWs from which information
about the entities on the current server can be queried. At least the
docs discuss what a SCHEMA is, within the context of the DB2 for i, in
contrast with the usage of the term by most other RDBMS; there is AFaIK,
*no* similar discussion of the term /catalog/, so only those familiar
with non-DB2 for i would be generally well informed of what is the meaning.
So my implication was, that by "IBM" telling someone who is using the
DB2 for i, that the SCHEMAS are entities\components of a CATALOG, is
little better than having suggested to that interested party that the
SCHEMAS are entities\components of a CABINET; i.e. the term CABINET will
have a similarly useful meaning [almost none], within the context of the
DB2 for i, as does the term CATALOG, at least with the effective meaning
as /container/ of SCHEMAS. IOW, talking to most long-term DB2 for i
users, and any mention that there is a CATALOG that contains the
SCHEMAS, and they will almost certainly conflate the term with the
Catalog VIEWs; and many probably would be adamant, insisting that
instead the library QSYS contains SCHEMAS, because the catalog is just
row-data.
If the "IBM" were inclined to use effective column-names to describe
the situation, then they could have offered instead, an explanation
using only column-names: that each COLUMN_NAME is grouped within each
TABLE_NAME which is grouped within each TABLE_SCHEMA which is grouped
within each TABLE_CATALOG which is derived from a CATALOG_NAME [or just
as accurately, derived from the special register CURRENT SERVER].
midrange.com
