Edit a dGraph
Once you have completed the import (or opened a file), the dGraph editor is displayed. The first screen is the dGraph name and primary table you have already defined. Press the next button and all of the database tables are displayed. Choose the tables with which you wish to work and on subsequent screens the list of columns will be filtered. The example used for this demonstration is the Autos project provided with the install.
Choose Tables
You most like will not want to use all tables in your database. Use the table select screen to move the tables of interest to the right side. This will make them available in later screen for field selection. This narrows down the data you will need to week through to build a dGraph.
Choose Fields
Moving on to the next screen, you may then choose which fields with which to work. Move the field to the right side of the screen you wish to use in the dGraph. All other fields on the left will not be included in the dGraph.
Setup Fields
Press the next button will take you to the field details screen. Listed are all of the fields that you have chosen as necessary for the dGraph. The properties of the field will be shown in the properties window when it is highlighted. The properties of each field allow you to define functionality of the dGraph. You can choose to show the field with the record. Also you can set its properties to determine if it is included in filters, sorts, or searches.
Special Fields
Most of the data you will need is defined in your database fields. However there are times when you need special fields that a database does not provide. There are several of these that you can define as a dGraph field.
Indexing Criteria
Press the next button to edit a list if indexing criteria. This is a list of columns and values that will be used to filter the data to be indexed. If you wish to select all data in your database that match the primary table and satellite tables, there is no need to add any indexing criteria. However if you wish to filter data before indexing, define that criteria on this screen. For example, your primary table may have an "Active" field and you wish only to list objects that have are active. In this case, there is no need to index inactive objects so we add an indexing criteria where active equal true. When the index is being built only matching records where the "Active" field is true will be selected. Pre-index filtering keeps your database size down and makes the CeleriQ engine faster as it never uses these excluded records in its index.
Defining Dimensions
The next screen is the Dimension Setup. You can define fields as dimensions and that can be used in Piloted Navigation. Dimensions are non-unique fields that are useful for user to use in filter down a result set. There are four types if dimensions: normal, list, range, and date.
Defining Rollups
After defining dimensions, press the "Next" button and go about defining rollup fields. Rollups are essentially aggregated data. This is analogous to the "GROUP BY" clause in SQL. When editing fields of the dGraph, you need to mark the field as a rollup. This provides the field with the ability to be used as a rollup field. This means it is valid to use it in the Rollup clause when querying. Aggregated records do not return the full set of properties like normal records but return only derived fields (see below). By default a representative record is returned as well. This is an arbitrary record that falls within the rollup parameters. Since a rollup is a grouping of record there are usually many more matching records. You can programmatically get all of them as well if needed.
After a rollup field is defined, you can then add derived fields for the operation. Derived fields are analogous to the aggregate functions in SQL: sum, average, min, max, and count. These allow you to aggregate fields and create a new type of rollup record. Fields can also be eliminated from rollups by the architect, limiting what software developers can use. This may be required by business rules.
To add a rollup select a field in the left list and press the "Add Rollup" button. This will add a new rollup to the right list. Highlight the new rollup field and its properties are visible in the properties pane. From there you can define the derived fields.
Derived Fields
In addition to grouping records by some commonality, there is also the ability to aggregate fields. In other words, data can be truly rolled up based on the underlying set. Derived fields do not exist in your database but are calculated on the fly. They are essentially calculated fields. In a dGraph, you can define fields that should be aggregated based on a data dimension using sum, min, max, count, or average. In the automobile dGraph example, you could define derived fields minimum miles per gallon and maximum miles per gallon. When a rollup operation is performed on a dGraph by the dimension "year", there would be extra fields added to the returned result set that map to these calculations. To software developers it is just another data field. This gives you the flexibility to provide users with all sorts of aggregated data based on very specific data layouts.
Summary
The final screen is for summary information. This screen will summarize your dGraph. You will find information on dimensions and rollups. Also you can find searchable, sortable, and filterable fields. Press the "Build" button to start the indexing process. You will be prompted for the build settings before the index is started.
