Re: V7.0 Rowid ...
jon,
} At 09:49 AM 7/12/95 GMT, russell@excelsis.demon.co.uk wrote:
} >Wotcha peeps - there seems to be some controversy as to whether rowids exist
} >in V7.0/7.1 Online.
} >
} >Could someone Please confirm this.
}
} ROWIDS do exist in version 7.x However:
} - If you fragment a table, ROWIDS are no longer unique within the table
} (i.e. each fragment is essentially a table, and has its own ROWID set).
have you actually tested this? in our testing, we found rowid to be unique
across the table, not just fragments...
} - If you do NOT fragment a table, then ROWID exists as it did before.
} However, Informix has continually stated that this may change. Save yourself
} some time and grief, and start thinking about removing ROWID from
} applications, and move toward primary keys.
} - If a table is fragmented, you can create or alter the table to create a
} rowid column (RTFM ver7 syntax for create/alter table).This was put in,
} because so many people were using them. When you do this though, you
} essentially add a new serial column to the table, and it becomes indexed. At
} this point, it behaves just as any other indexed column, and carries the
} associated overhead of such. So, again this is another reason to use primary
} keys, you reduce the schema by 4 bytes, plus the index overhead.
}
not exactly, try creating a fragmented table with rowids then doing a
oncheck -pe.
} I believe I covered the particulars of ROWID's with version 7, and I hope
} this answers your question.
}
} Jon
} ==================================================================
} Jon Vemo Internet: jvemo@cyberspace.com
} Bothell, WA USA
} ------------------------------------------------------------------
} Watch out for road-kill on the information superhighway....SPLAT!!
} ==================================================================
}
}
--
regards,
+----------------------------------------------------------------------------+
| . . | Bob Baskett |
| ... ... | Software Engineer |
| ..... ..... | Business Systems Integration Group |
| .. ... .. | Semiconductor Products Sector |
| . . . | Mesa, AZ |
| | President, Informix Users Group Of Arizona |
| Motorola, Inc. | rzbj40@email.sps.mot.com |
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