Consultor Eletrônico

SUMMARY:

When dumping tables from Progress 8.x and earlier into Progress 9.x, DBANALYS reveals that tables dumped and loaded into the Progress 9.x database are larger than the original tables, even though they contain identical data. This also applies to older databases that are converted to Progress 9.x using the conv89 utility.

EXPLANATION:

Each record in Progress 9.x requires additional bytes, which contain schema version mapping information. This allows schema changes to be done without updating each existing record. This same information also allows logical column ordering to be different from stored column ordering, which enables table CRCs to be independent of the order in which schema changes are made.

When converting from Progress 8.x to Progress 9.x, the additional byte information is not initially added. The byte information is added as records are updated. Newly created records thereafter will automatically have the additional byte information included.

To Demonstrate:

In this example, a Progress Version 8.x Sports database Customer table size, as reported by DBANALYS, is:

Table Records Size Min Max Mean Count
Factor Factor
Customer 83 11.1K 106 210 137 83
1.0 1.5

A dump and load of the Customer table into an empty Version 8 database reveals that the table size remains the same:

Table Records Size Min Max Mean Count
Factor Factor
Customer 83 11.1K 106 210 137 83
1.0 1.5

Running a conv89 on the database, the Customer table remains the same:

Record Size (B)- ---Fragments---

Scatter
Table Records Size Min Max Mean Count
Factor Factor
PUB.Customer 83 11.1K 106 210 137 83
1.0 1.5

However, if the Customer table is dumped and loaded from either Progress Version 8.x or Progress Version 9.x into an empty Progress Version 9.x database, DBANALYS reveals:

-Record Size (B)- ---Fragments---

Scatter
Table Records Size Min Max Mean Count
Factor Factor
PUB.Customer 83 12.1K 118 222 149 83
1.0 2.2