Navigating the G/Tech Metadata with GTI’s Metadata Explorer (GTMetaExp) – Part 2

In a previous posting, GTI introduced a new tool called the GT/Metadata Explorer, or GTMetaExp for short. This tool was designed specifically to look at Intergraph’s G/Technology Metadata in an Oracle Database. While Toad is another tool for performing this same task, the GTMetaExp is specifically designed to navigate through the metadata without hacking together queries and scripts. We have been beta testing GTMetaExp over the last few months and have received much positive feedback. We have listened to the beta testers and have added a substantial amount of new functionality to GTMetaExp to make it even more useful. This Part 2 posting on GTMetaExp will cover the new functionality we have added including the Find Feature tab, the Connectivity Search, and the Ownership Search.

Since its initial release back in December, GTMetaExp has had a few cosmetic changes. Its main form is now resizable to take advantage of larger screens, a Feature Filter was added to the Features and Components tab to make it easier to locate a feature, and column sort capabilities were added to every List View in the application. Ownership Relationship information was added to the Features and Components tab, and a handful of fixes and other tweaks were made also along the way.

This posting is concerned with the new functionality and most of it is located on the Find Feature tab. This new tab does exactly what its name implies; it will find a feature in the GIS database. Technically, this new functionality is moving beyond pure metadata exploring and into data exploring, but since finding a feature in the GIS Database is heavily dependent on the metadata, we haven’t felt it necessary to change the name of the product. Since the initial version, GTMetaExp has been able to produce a Style and Label Rule Usage Report which is also data dependent and not purely exploring the metadata, so the new functionality is not that far removed from our initial intent of the product.

Find Feature

The Find Feature tab will let you find a specific feature in the GIS data with 3 different query methods: Find by Attribute Value, Find by G3E_FID, and Find by Predefined Query.

Find By Attribute Value is probably the most flexible of the three methods and possibly the most useful. This query method allows you to select a Feature Type that you want to query (from the Features list), then it will present a list of all tabular components associated with that feature. The Primary Tabular Component is selected by default, but you can select any of the available components from the component dropdown list. With a Component selected, the Attribute/Value List View is populated with all available Attributes associated with the feature’s selected component.

You can select any attribute in the list and provide a value. When the Search button is pressed, the feature’s component table is searched for all records that match the value provided. If more than one attribute value is provided, the criteria are ANDed together. The records are also filtered by the feature’s number (G3E_FNO) so that only records belonging to the selected feature will be returned (in case you are searching a shared table like Common or Connectivity).

The icons to the left of the Attribute name tell the kind of value is expected for the attribute:

While you can always enter a value, special types like Dates and Lists will have a drop down to assist in entering their value. A Date Type will use a Date Picker and a List will use a ComboBox containing all of the values of the attribute’s associated Pick List.

When the Search button is pressed, all records matching the search criteria are shown in the Results List View.

Find by G3E_FID is a specialty query method. When you only have a G3E_FID, this query will search all feature tables until a feature is found with the specified G3E_FID value. Enter a G3E_FID in the prompt and press the Search button to perform the query. The Common and Connectivity tables are searched first since they will likely contain the feature; however, if the feature is not found, all feature tables will be searched.

Using the Find Feature Results

The Find Feature Results List View is populated when the Search button is pressed on one of the query tabs. The results can be sorted on any column by clicking the column header. The results can also be copied to the Windows Clipboard.

If you select a record in the results, you have three options to choose from: Attribute Info, Connectivity Search, and Ownership Search.

Attribute Info

The Attribute Info option (also activated by double-clicking on a result record) will display all of the available tabular attribute information for the selected feature. The attribute information is displayed in a GTViewer-style Attribute Info form where each tab is one of the feature’s components.

By default, the Attribute Info is shown using the Component and Attribute User Names as they are defined in the metadata. However, the radio buttons across the top of the form can be used to change the display names to their actual database names or a combination of the user name and database names.

You can show several Attribute Info forms at the same time so that a comparison can be made between different features. The Copy button is also available to copy the active tab’s contents to the Windows clipboard.

Connectivity Search

The Connectivity Search feature will visually show all features connected to the selected feature in the Query Results. The selected feature and its immediate neighbors are then represented in a simplified graph view. The Connectivity Search is intended to help identify problems in the connectivity by quickly visualizing how the connections are represented in the database.

The Connectivity Search can visualize the data in two different ways: Features as Links and Features as Nodes. The visualization method is selected in the lower left corner of the Connectivity Search form and defaults to Features as Links method.

The Features as Links method is useful for identifying problems in connectivity records because it represents the connectivity information exactly as it appears in the database, only in a visual format. Connectivity Nodes are shown as pink circles while features are shown between the nodes as blue ellipses (linear features) and orange ellipses (point features).

The Features as Nodes visualization method represent only the features as nodes in the graph (blue for linear features and orange for point features) with connectivity records shown as the links between the features. This approach uses fewer nodes in the graphic, but the number of links can be greater as trace steps are added. This view of the data may often be useful when examining connectivity problems as it shows a more real-world view of the data versus the connectivity table representation.

Both Connectivity Search Visualization Methods support the Trace Next Step button which will find all features connecting to the features currently in the view. Trace Next Step can be used as long as there are more connecting features. While the graph may quickly become very busy, tools are provided to help manage the view. The Zoom In and Zoom Out buttons will control the current view scale and scroll bars along the view’s bottom and right provide panning capabilities. The Fit All button will fit the entire graph in the view, and the Reset Trace button will return to the initial feature and its immediate neighbors. The Print button will allow the graph to be printed.

Hovering the mouse cursor over any node in the graph will display Tooltip information about a node including the feature’s connecting Node values, Fid, FNo, CNo, Cid, and Id.

Pressing the Right Mouse Button on a node will give two options: 1) Restart the trace from this Node or 2) Show Attribute Information for feature associated with this Node.

Ownership Search

The Ownership Search will visualize the selected feature in the Query Results and all features sourced to or owned by the selected feature. The Ownership Search will iterate through the features until no new features can be found.

In the Ownership Search results below, the starting feature is always shown in Orange while all of the other features are shown in Blue. The connecting links point to the owner. In the example below, the OH Transformer is the starting feature and is owned by the Pole. The Pole also owns three Secondary Conductors and a Down Guy.

A more complex example is shown below:

The Ownership Search form provides view control with the Zoom In, Zoom Out and Fit All buttons. Panning can be performed with the scroll bars along the bottom and right of the graph view. Like the Connectivity Search, Tooltips will also be shown for each node in the graph and a Right-Mouse Click on a now will provide the option to display Attribute Info for the associated feature.

Summary

The new capabilities added to GTMetaExp broadens its potential user base. A variety of uses can be found for the Find Feature functionality which extends beyond ability to explore the metadata. GTMetaExp will continue to be in beta until the end of the year, and a beta version will be provided upon request (support@gti-us.com).

Navigating the G/Tech Metadata with GTI’s Metadata Explorer (GTMetaExp) – Part 1

GTI has gained considerable experience with Intergraph’s G/Technology metadata through the development of our export tools that take GIS data out of Oracle and into the GTViewer format (which can then be used with GTViewer, Pocket GTViewer, and/or GTWeb). GTI’s G/Tech Exporter is now in its fourth generation and offers better support and flexibility for quickly and accurately getting graphic and tabular data out of a G/Tech database. The current incarnation of GTI’s G/Tech Exporter provides a full GUI interface, provides dynamic style and label rule evaluation, and automatically extracts style and symbology information. The Exporter is a heavy user of the G/Tech Metadata when exporting the GIS data, so it was a small leap for GTI to reuse some of this technology in a tool other than the Exporter, and the GTI Metadata Explorer was born.

As many people who deal with G/Tech data know, Toad has been the tool of choice for navigating the G/Tech metadata. The G/Tech metadata contains all of the information describing the GIS and ranges from the list of features and their components, relationships between features, Display Legend info, to symbology. By using Toad’s Schema Browser or by executing home brewed SQL scripts, you can find anything you want to know in the metadata. And while I love Toad (I really do) and all it can do, and fully agree that this method of exploring the metadata is significantly better than what you could do with SQL*Plus or any of the G/Tech utilities, Toad doesn’t know anything about the G/Tech metadata or how the many tables interrelate. It should also be pointed out that Toad shouldn’t know these relationships because it is a database administration and SQL development tool, not a metadata viewer.

It is easy to illustrate the complexity of the metadata just by posing a simple question: “What are the components of a Pole feature?”

First, you need to find the Feature Number for a Pole Feature:

select *
from g3e_feature
where g3e_username='Pole';

Then use the feature number (208) to find the pole feature’s components:

select * from g3e_featurecomponent a, g3e_component b
where a.g3e_fno=208 and a.g3e_cno=b.g3e_cno
order by a.g3e_ordinal;

And you still have to wade through the entire list attributes for the joined table results to get the information you need. If you want to see all of the attributes for one of the tabular components, then SQL gets even more complicated.

With the GTI Metadata Explorer, you simply navigate from Feature to Attribute. To find information out about a Pole, just select it in the feature list:




Clicking on a feature will display all of its component information:





If you want to know the attributes for one of the feature’s tabular component, click on the tabular component in the list.




If you have an attribute associated with a value list, click on the attribute and to get a list of the values.


All together this process looks like the following:



The GTI Metadata Explorer does much more than navigate through the Feature/Component relationships. Other features include the:

Feature to Style functionality which allows the user to navigate from a Legend, to a Features, to the Style Rules, to the Style and Symbology. This feature will be discussed in detail in a later posting, but here is a screenshot of the information it can provide:




Another feature the explorer provides is a set of Validation routines. The correctness of certain aspects of the metadata can be verified.

• Style Rule, Label Rule, and Label Format validation routines are provided to test the correctness of the expressions used in the metadata rules. It turns out that there are quite a few mistakes in these expressions that G/Tech does not catch and these validation routines can quickly identify them.
• Other validation routines can detect Unreachable Rules. It is common to see in G/Tech data a list of rules for a feature where one or more rules have the same conditional expression. Obviously, something is wrong with these style rules because the first rule with the expression will always trigger the associated style and the duplicate(s) will never be reached.
• Legend Validation will analyze a legend’s hierarchical structure and verify that there is a leaf node for legend level of the legend. It is not uncommon to see 3 levels of grouping, but no features at the lowest node.
• Geometry Property Validation will search for obvious problems in a geometry table’s attributes. Whether these problems come from bulk data conversion when migrating from classic Framme data or from some other process, it is not uncommon to have poorly constructed geometry records in a G/Tech database. This validation is not technically testing metadata correctness since it is examining each geometry record in the database, but it is a useful test none the less.

More detailed information about the validation routines will be in a later posting.

One of the more interesting features of the GTI Metadata Explorer is the Summary Report feature. This report allows the user to select a set of features from a particular legend, then create a summary report for those features that will tell the number of times each style rule and label rule are used for the current data. This report is ideal for testing the integrity of both your data and metadata. For example, if you have no retired poles in your data, but the summary report show that there are 500,000 poles using the Retired Pole symbology, you know there is a problem that should be investigated. The report will also provide a quick and easy view of the usage of your style and label rules which is not something you can do by simply querying the database with Toad.



This posting just gives a taste of what the GTI Metadata Explorer can do. More postings will be added later describing the features in more detail. The Explorer is currently a beta application, but if you would like to try it, please contact me (joey.rogers@gti-us.com), and I will get you started in the beta program.