Data is stored in blocks or records, within a file, and each record is identified by a unique name called a pathname. Each time that data is stored or retrieved from the file, its pathname must be given. The pathname is the key to the data's location in the database. A pathname is analyzed by DSS to determine an index number. This index determines where the dataset is stored within the database. The design ensures that very few disk accesses are made to retrieve or store datasets. One dataset is not related to another, so there is no need to update other areas of the database when a new dataset is stored.

DSS references records (datasets) by a pathname. The pathname of a DSS record can be three hundred and ninety-one (391) characters or less, and is, by convention, separated into six parts. The parts can be sixty-four (64) characters or less and are delimited by slashes in the pathname. The pathname parts are designated A through F. Table 1 provides an example naming convention for regular-interval time series:

A pathname may consist of up to 391 characters and is, by convention, separated into six parts, which may be up to sixty-four characters each. Pathnames are automatically translated into all upper-case characters. They are separated into six parts (delimited by slashes "/") labeled "A" through "F," as follows: /A/B/C/D/E/F/. Table 1 provides an example naming convention for regular-interval time series. A typical regular-interval time series might be:
/RED RIVER/BEND MARINA/FLOW/01JAN1995/1DAY/OBS/.

Table 1 DSS Pathname Parts

Viewing DSS Pathnames

The display of DSS pathnames in the Pathname Table (HEC-DSSVue Dialog) shows all the pathnames by their different parts. This display can be changed from the View menu. Available commands are Pathname List, Pathname Parts, Condensed Catalog, Condensed – Group Collections, No Pathnames, and Unsorted List.

The Pathname List command (Figure 1) displays the pathnames in the Pathname Table, while No Pathnames displays nothing. The Pathname Parts command (Figure 2) is the default view. Condensed Catalog is like the Pathname Parts command, but Part D displays a date span for each DSS pathname. The Unsorted List command displays the same as the Pathname List command, but you can automatically search pathnames by a string.

Search DSS Pathnames by Parts

Another way to change the display of the DSS pathnames is by searching pathnames by pathname parts. By default, you can search DSS pathnames by parts (Search pathnames by part). To search by pathname parts, from the Pathname Filters (Figure 3), decide which DSS pathname parts will be used. There is a Filter List for each individual pathname part. An example is shown in Figure 3, where DSS filters are used to see all the STAGE records that are were acquired from USGS. From the Filter C list, select STAGE, and from the Filter F list, select USGS. The Pathname Table displays only the pathnames that fit the criteria selected from the Filter Lists.

Another way to search pathnames is by providing a "string for the search. From the View menu, click Search pathnames by string. The pathname filters are replaced with a Search Pathnames box (Figure 4), and a Search button. For example, in Figure 4, in the Search Pathnames box, Big Sulphur has been entered. Click Search, the Pathname Table displays all records that contain Big Sulphur. Further details for this method are described in the HEC-DSSVue User's Manual.

Selecting Pathnames

With the appropriate list of pathnames in the Pathname Table (HEC-DSSVue Dialog) select which pathnames to view or manipulate. To select a pathname, double-click on a pathname in the Pathname Table, and the selected pathname will appear in the Selected Pathname List (HEC-DSSVue Dialog). Alternatively, click on a pathname in the Pathname Table, and then click Select.

To select multiple pathnames, in the Pathname Table, click on a pathname the pathname will be highlighted. Find the next pathname to include in a group, hold down the SHIFT key and click. The block of pathnames will be highlighted. Click Select, and all the pathnames within that block will be added to the Selected Pathname List. Another way to select multiple pathnames is from the Pathname Table. Click and drag across the pathnames, release the mouse button and the block of pathnames will be highlighted. Click Select, and all the pathnames within that block will be added to the Selected Pathname List.

Individual pathnames can be selected to be in a group for selection. From the Pathname Table, select a pathname which will be highlighted. To select another not in a contiguous group, hold down the CTRL key and select the next pathname which will be highlighted. Continue to do this until all of the desired pathnames have been selected. Release the CTRL key and click Select. All the selected pathnames will be added to the Selected Pathname List.
You can select all pathnames displayed in the Pathname Table, from the Edit menu, click Select All. All of the pathnames available from the selected DSS file will now display in the Selected Pathname List (HEC-DSSVue Dialog).

Clearing Selected Pathnames

To clear a pathname from the Selected Pathname List (HEC-DSSVue Dialog), select a pathname and click De-Select. The pathname will be cleared from the Selected Pathname List. To clear all pathnames from the Selected Pathname List, click Clear Selections.

Groups of pathnames can be cleared by using the same concepts described in selecting pathnames by using the SHIFT and CTRL keys. Once pathnames have been cleared from the Selected Pathname List, the pathnames can be restored to the Selected Pathname List by clicking Restore Selections.