• MultiClassification

MultiClassification

Requirements

• unlimited number of classifications for one document (task)
• unlimited number of assigned aspect values in one aspect

Solution

Separate Classifications records are used for every classification which is set. No empty records used, a document has as many Classifications records as many classifications are set.

Issues

1. How to handle auto-classification from the drawing code? E.g. do you create a new (additional) classification, or (all?) replace
   • existing classifications?

Detail

No problems determined until now. A smarty loop goes through all Classifications records to display them line to line.

New/Update

For every aspects defined in table Aspects at least one line appears even if it is empty. At the right side of all line there is a new button to open additional line for entering classification in the same aspect, and a delete button to remove that classification. If there is no more classification in an aspect (after deleting the last one) an empty line appears.

Search

Searching is a performance issue. Because of all Classifications are different records a large joins could be used to perform searching, which can be very slow. The following optimization steps will be implemented:

1. determine first the number of Classifications records involved in one aspect value search

2. perform a nested select with the smallest records set in the inner most level to limit the involved records to the minimum. The result should be saved into a temp table in the database. This temp table should be deleted at every new search or list.

3. read DrawingsRevisionsJoinSet with the id set got from the select above

E.g.: assumed that we are looking for documents with aspect codes 22, 345 and 42, the steps above:

 1. select code, count(*) from Classifications where code in ( '22', '345', '42' ) order by 2;

 +------+----------+
 | code | count(*) |
 +------+----------+
 |  345 |       10 |
 |   42 |      234 |
 |   22 |     1410 |
 +------+----------+

 2. select objectId from Classifications where objectTypeId = ... and code = '22' and object Id in (
      select objectId from Classifications where objectTypeId = ... and code = '42' and object Id in (
        select objectId from Classifications where objectTypeId = ... and code = '345'
      )
    )

List

Displaying of classifications in a document list is also a performance issue. To be able to display classification information quickly a static database table will be used to store some information about classified documents:

AspectCache Table

There is one record for one object (Drawing, Task). The field full code is a comma separated list of all aspect values in the appropriate aspect assigned to the object. On a document list with classifications the min code, max code can appear according the sorting order. On a non-sorted list the full code can appear or it can be a site setting parameter.

Issue

The AspectCache table can be updated:

1. database procedures on regularly basis (cron?)
2. fired by triggers on the tables Drawings, Comments and Classifications
3. by application transactions

Listing Multiple Classification Values

Three cases are possible:

1. One classification, with a single from-to pair (E.g. one chainage range on a single alignment)

   • Display: Code x->y -- or code only, with no values?

   • Hover: Name x->y

2. Multiple classifications on same classification, with different from-to pairs (e.g. multiple chainage ranges on a single alignment)

   • Display: Code min-x -> max-y...

   • Hover: Name min-x -> max-y (multiple)

3. Multiple classifications on different classification, with different from-to pairs (e.g. multiple chainage ranges on multiple alignments)

   • Display: Code-mix, Code-max... -- Or can we display something more sensible?

   • Hover: Name-min, Nam-max...(multiple)

We don't need to make a decision now, as the display only changes the update that fills the aspect cache table.