Сравнение SQL Server 2008, PostGIS, MySQL

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General Overview

Feature	SQL Server 2008 (RC0)	MySQL 5.1/6	PostgreSQL 8.3/PostGIS 1.3/1.4
OS	Windows XP, Windows Vista, Windows 2003, Windows 2008	Windows XP, Windows Vista, (haven't tested on 2008), Linux, Unix, Mac	Windows 2000+ (including Vista and 2003, haven't tested on 2008), Linux, Unix, Mac
Licensing	Commercial - Closed Source, Various levels of features based on version, Express version has full spatial support but limitation on database size and only use one processor.	Commercial Open Source (COSS), some parts GPL. Here is an interesting blog entry on the subject MySQL free software but not Open Source. The comments are actually much more informative than the article itself.	FLOSS (PostgreSQL is BSD, PostGIS is GPL Open Source - you can use for commercial apps but if you make changes to the core libraries of PostGIS, you need to give that back to the community)
Free GIS Data Loaders	shp dataloader for SQL Server 2008 developed by Morten Nielsen(doesn't yet work with RC0)	OGR2OGR, shp2mysql.pl script	included shp2pgsql, OGR2OGR, QuantumGIS SPIT,SHP loader for PostGIS also developed by Morten using SharpMap.NET various others
Commercial GIS Data Loaders	Manifold, Safe FME Objects, ESRI ArcGIS 9.3 (in a later service pack)	Safe FME Objects	Manifold, FME Objects, ESRI ArcGIS 9.3
Application drivers available specifically for spatial component	? Not yet - SharpMap.NET eventually and probably built into new ADO.NET 3.5+	GDAL C++, SharpMap via OGR, AutoCAD FDO	SharpMap.Net, JDBC postgis.jar included with postgis, JTS etc. tons for Java, GDAL C++, AutoCad FDO beta support
Free Object/Relational Mapping	NHibernateSpatial (this is a .NET object relational spatial mapper) - beta support	Hibernate Spatial - this is a java object relational mapper	NHibernateSpatial and HibernateSpatial
Free Desktop Viewers and Editors	Will be built into SQL Manager, but not available in RC0 and only useful for viewing	GvSig	OpenJump, QuantumGIS, GvSig, uDig
Commercial Desktop Viewers and Editors	ESRI ArcGIS 9.3 Server SDE later service pack, Manifold, FME	FME	ESRI ArcGIS 9.3 Server, ZigGIS for desktop, Manifold, FME
Web Mapping ToolKits - it must be said things like OpenLayers and various other scripting frameworks that can accept GML will work with any of these databases and your favorite web scripting language	Manifold, MapDotNet, ArcGIS 9.3 (in later service pack), UMN MapServer see, MapGuide Open Source (using beta FDO driver)	UMN Mapserver, GeoServer, MapGuide Open Source	Manifold, MapDotNet, ArcGIS 9.3, UMN Mapserver, GeoServer, FeatureServer, MapGuide Open Source (using beta FDO driver)
Spatial Functions	Both OGC SFSQL MM and Geodetic custom (over 70 functions)	OGC mostly only MBR (bounding box functions) few true spatial relation functions, 2D only	Over 300 functions and operators, no geodetic support except for point-2-point non-indexed distance functions, custom PostGIS for 2D and some 3D, some MM support of circular strings and compound curves
Spatial Indexes (from reports Oracle also uses some sort of R-Tree indexing scheme and can use quadtree, IBM DB2 uses quadtree, Spherical Voronoi Tessalation, IBM Informix uses R-Tree. Note R-Tree indexes are self-tuning and do not require grid setup	Yes - 4 level Multi-Level grid hierarchy (BOL says its B-Tree based) with tessalation as described Isaac Kunen Multi-Level Gridrequires defining an index grid for optimal performance	R-Tree quadratic splitting - indexes only exist for MyISAM	GIST - a variant of R-Tree
True Geodetic support - support for true measurement along a spherical coordinate (it must be noted Oracle and IBM provide geodetic support, although IBM Informix/DB2 have it as an additional Blade add-on in addition to standard spatial)	Yes - with caveats - must use Geography type which has the following constraints, no single geometry may overlap hemispheres, intersections, some operations are undefined for two geometries in separate hemispheres. SRID must be defined in spatial ref. Orientation of polygons is important in Geography. According to BOL - ST_Distance is only supported when one of the geography instances is a point ( NOTE: Isaac Kunen says the BOL docs are wrong about ST_Distance and this restriction has been lifted) . Fewer spatial functions available for geography than geometry	No	No
Shared Hosting	Many	Many	Much fewer, but ramping up. It must be noted that if you have a dedicated Linux/Windows server, and aren't afraid to be your own admin (or to get a qualified consultant such as us), then your options are much wider.List of community recommended PostGIS Hosters

Spatial Functionality

Feature	SQL Server 2008 (RC0) Geometry	SQL Server 2008 (RC0) Geography	MySQL 5.1/6	PostgreSQL 8.3/PostGIS 1.3/1.4
Supported Geometry Types	Polygon, Point, LineString, MultiLineString, MultiPoint, MultiPolygon, GeometryCollection 2D support also storage for 3D and 4D (M,Z)	Polygon, Point, LineString, MultiLineString, MultiPoint, MultiPolygon, GeometryCollection, 2D, ability to store 3D, 4D (M and Z)	2D, can store 3D 4D(e.g. M and Z) but no functions do anything with those) - Polygon, Point, LineString, MultiPoint, MultiPolygon,MultiLineString, GeometryCollection	2D, some 3D, 4D (support for storing Z,M but most spatial functions ignore the higher dimensions) and some curve support - Polygon, Point, LineString, MultiPoint, MultiPolygon, MultiLineString, GeometryCollection, CircularString, CompoundCurve, CurvePolygon, MultiCurve, MultiSurface
Transform - ability to transform from one spatial ref to another	No - need 3rd-party tools, Geometry can use any SRID between 0 and 999999	No, but less need for transform since spherical coordinates that cover the globe can be used. SRID must be defined in sys.spatial_reference_systems	No	ST_Transform - Yes for 2D and 3D, but not for Circular Curve Types
Geometry Output functions - these are important particular for web-development when using the various javascript, flash apis	STAsBinary(), STAsText(), AsGML(), AsTextZM(), will have a builder api in the RTM for extending to support more output formats	Same as the geometry ones	AsBinary(), AsText()	ST_AsBinary(), ST_AsText(), ST_AsSVG(), ST_AsGML(), ST_AsKML(), ST_AsGeoJson() -- new in 1.3.4, ST_AsEWKT(), ST_AsHexEWKB()
Geometry Input functions	STGeomFromText(),STGeomFromWKB(), GeomFromGML()	Same as Geometry	GeomFromText(), GeomFromWKB()	ST_GeomFromText(), ST_GeomFromWKB()
Intersects and Intersection	STIntersects(), STIntersection() (spatial ref of both geoms must be the same)	Same as geometry except an intersection resulting in a polygon that overlaps 2 hemispheres will return null	MBRIntersects()* bounding box only (spatial refs of both geoms must be the same), they do not implement Intersection yet	ST_Intersects(), ST_Intersection() (spatial ref must be the same)
Other Non-Agg key relationship and relation outputs	STContains(), STDifference(), STDisjoint(), STEquals(), STOverlaps(), STRelate(), STSymDifference(), STTouches(), STWithin()	STDisjoint()	MBRContains(), MBREqual(), MBROverlaps, MBRTouches(), MBRWithin(), bounding box only (spatial refs of both geoms must be the same) (these are aliased in 6.0 to names Contains(), Overlaps(), Equals()... but do the same as MBR)	ST_Contains(), ST_Disjoint(), ST_Difference(), ST_Equals(), ST_Overlaps(), ST_Relate(), ST_SymDifference(), ST_Touches(), ST_Within() (spatial ref must be the same)
Accessors and Editors	BufferWithTolerance() (this is similar to PostGIS variant of Buffer that takes 3 args (defaulted to 8 number of segs to use to approximate a quarter circle), MakeValid(), Reduce() - similar to PostGIS ST_Simplify(), STBoundary(), STBuffer(),STCentroid(), STConvexHull(), STDimension(), STEndPoint(), STExteriorRing(), STGeometryN(), STGeometryType(), STInteriorRingN(), STIsClosed(), STIsEmpty(), STIsSimple(), STNumGeometries(), STNumPoints() (only applies to LINESTRINGS), STPointN((), STStartPoint(), STSRID(), STUnion()	NumRings(), RingN(), STArea(), STBuffer(), STDimension(), STEndpoint(),STGeometryN(), STGeometryType(), STIsClosed(), STIsEmpty(), STLength(), STNumGeometries(), STNumPoints(), STPointN(), STSrid(), STStartPoint(), STUnion()	Centroid(), Dimension(), EndPoint(), Envelope(), ExteriorRing(), GeomtryN(), GeometryType(), InteriorRingN(), IsClosed(), IsRing(), NumPoints(), PointN(), SRID(), StartPoint()	ST_Affine(), ST_Boundary(), ST_Buffer() (2 variants similar to STBuffer() and BufferWithTolerance()), ST_Centroid(), ST_ConvexHull(), ST_Dimension(), ST_EndPoint(), ST_ExteriorRing(), ST_GeometryN(), ST_GeometryType(), ST_InteriorRingN(), ST_IsClosed(), ST_IsEmpty(),ST_IsRing(), ST_ISSimple(), ST_NumGeometries(),ST_NumPoints() (only applies to linestrings), ST_NPoints() - returns num vertexes regardless of geometry type, ST_PointN(), ST_Simplify(), ST_StartPoint(), ST_SRID(),ST_Translate(), ST_Union(), various MakeLine,MakePolygon, buildarea etc.
Measurement	STArea(), STLength(), STDistance() (measurements in unit of spatial ref)	Same as geometry - except measurements can be in meters, sq meters, or units of spatial ref	Area(), GLength(), Distance()	ST_Area(), ST_Length(), ST_Distance(), ST_Distance_Spheroid(), ST_Length_Spheriod (non-sphere, non-spheriod functions units are in spatial ref, sphere and spheroid are in meters but only work for point geometries) and equivalents for 3D geometries.
Linear Referencing - things like returning fractions of lines, approximating point location along a line based on num address	none built in, but can roll your own with CLR. UPDATE Isaac Knunen has some linear referencing functions already built in the new CodePlex SQL Server Spatial Tools project.	none built in - check out new SQL Server Spatial tools code plex project	none	ST_Line_Interpolate_point(), ST_Line_Substring(), ST_line_locate_point(), ST_locate_along_measure(), ST_locate_between_measures()
Spatial Aggregates (functions like SUM but for spatial)	Apparently none in this release so have to roll your own with CLR. There are numerous examples of this on the web. UPDATE SQL Server 2008 Spatial Toolscontains aggregate functions for Union and Envelop similar to PostGIS ST_Union and ST_Extent functions	none	none	ST_Extent(), ST_Collect(), ST_Union(), ST_Accum(), ST_MakeLine(), ST_Polygonize()