This thesis describes the spatial extensions of the existing non commercial databases for direct use in GIS. The work contains an overview of the current (major) solutions of the spatial extensions - PostGIS for PostgreSQL, MyGIS for MySQL, SpatiaLite for SQLite and JanGeoDB.
At the beginning of this work is to explain the concept of databases and other concepts of databases. The database can be viewed as one or more files stored on an external storage device such as a disk. DBMS (DataBase Management System) is a collection of programs that manage the database structure and controls access to data stored in the database. Geodatabase is a database designed for storing, querying and manipulation of geographic information and spatial data. It is also known as a spatial database. Within a spatial database with spatial data is treated as any other type of data. Vector data can be stored as point, line or polygon data types and may have associated coordinate system. Record geodatabase can use the geometry data type to represent the placement of the object in the physical world and other standard database data types to store attributes of an object. Some geodatabases may also include support for storing raster data.
Many geodatabases have their own functions to manipulate and query of spatial data using SQL. However, the spatial data in some geodatabases can be accessed only by the special client software. PostgreSQL has been that software pgAdminIII for MySQL was MySQL Query Browser and SpatiaLite was for SQLite. Of the three software would like to highlight the most sophisticated pgAdminIII, which contains a large number of tools and options for creating geodatabases and can very well mean the PostGIS spatial extension. Duration of operations is not long. Most order will take place immediately, others take a few seconds. This depends on the size of the data. Important here is the command to write the code correctly, who enjoy good quotes. PostGIS can also be used in GIS softwares QuantumGIS and Janitor. On the second I put SpatiaLite which, while not containing as many options as pgAdminIII, but for less demanding users is certainly sufficient. Duration of operations is again very fast. Advantage of creating geodatabases in this software is that the resulting database is stored on disk as a file. Third place belongs to my opinion, MySQL Query Browser, which is at first glance very intuitive and simple, but work with it, unlike the previous is not very comfortable. The operations again depending on data size, but usually take place immediately.
Other software solutions mentioned in this work are high-quality accessories to create databases. I picked up most QuantumGIS (QGIS) and FWTools. QGIS I used to show layers made in PostGIS and SpatiaLite and also to import shapefile into PostgreSQL. FWTools is a package that contains several useful tools for manipulating geographic data.
Communication with the database is through SQL. SQL is the standard nonprocedural relational query language, supported by a majority of the available database systems. SQL is the acronym of words Structured Query Language.
Tested orders CREATE, INSERT, DELETE, UPDATE, and SELECT are described separately for each software and at the end of each test command are evaluated differences in orders from individual databases.
KEY WORDS: database, geodatabase, spatial, command, geometry, data, extension, information.
© Libor KIMPL | Bakalářská práce | Vedoucí práce: RNDr. Vilém Pechanec, Ph.D. | Katedra Geoinformatiky UP Olomouc | 2010