The U.S. Army Corps of Engineers' Hydrologic Engineering Center Data Storage System, or HEC-DSS, is a database system designed to efficiently store and retrieve scientific data that is typically sequential.
Such data types include, but are not limited to, time series data, curve data, spatial-oriented gridded data, and others. The system was designed to make it easy for users and application programs to retrieve
and store data. HEC-DSS is incorporated into most of HEC’s major application programs.
Data in HEC-DSS database files can be graphed, tabulated, edited and manipulated with HEC-DSSVue, a Java-based visual utilities program. HEC-DSSVue is supported for
Microsoft Windows, Sun Solaris SPARC, and Linux.
These libraries are accessed by programmers who write code for applications that access HEC-DSS files. Code that is linked with the HEC-DSS Version 7 library (DSS7) can access either Version 6 or 7 files.
HEC-DSS is intended for programmers that write programs to work with HEC-DSS files in Java, C, and C# (.net) programming languages.
What is new in HEC-DSS Version 7
DSS 7 has new features, compared to the previous version 6, described in the table below. Version 6 files need to be converted to Version 7 to utilize the new features.
| Feature | DSS6 | DSS7 |
| Catalog | Separate .dsc
catalog file | Catalog is faster, with new search methods, and internal to DSS7 file. |
| Extended dates | Year: 0001 to 9999 | Year: –5,873,711 to 5,879,610 |
| File efficiency | | More efficient storage. Some files are 50% smaller for the same data |
| Max file size | 8GB | Tested up to 125GB (can go larger) |
| Paired data | Limits on size | Any length of paired data, with support for multiple curves |
| Pathnames | Upper case 'FLOW' | Case insensitive 'Flow' |
| Programming language DSS is built with | FORTRAN | C (with FORTRAN to also support DSS 6 alongside DSS 7) |
| Pseudo intervals (~1Day) | n/a | Stored as irregular but typically follows regular pattern. |
| Threading | Single | Multi readers |
| Time series ensembles | | F part has c:xxxxxx| where xxxxxx is the collection sequence. /YUBA/SMARTSVILLE/FLOW/01JAN1997/1HOUR/C:000042|OP A/ |
| Time series profiles | n/a | Allows storing/plotting data such as water temperature profile. For example water temperature time series at different depths stored as a package (time series of time series) |
| Un-delete | Deleted records are marked unused (and could be restored) | Can't un-delete. However DSS7 files often have a on disk size much smaller that DSS6. |