PostGIS Writer: User Attributes

User attributes for this format are defined below.

Name

The name of the column to be written.

Valid values for column name include any character string that contains valid SQL characters, and is less than 32 characters in length.

Type

The type of a column in a table. The valid values for the column type are listed below:

Index

The type of index to create on the given column. All index types are fully dynamic and do not have to be optimized periodically. The valid values for the index type are listed below:

  • BTree – This index type is an implementation of Lehman-Yao high-concurrency B-trees. Only this type supports multi-column indexes. Up to 16 keys may be specified by default.
  • RTree – This index type is an implementation of standard R-trees using Guttman’s quadratic split algorithm.
  • Hash – This index type is an implementation of Litwin’s linear hashing.
  • PrimaryKey – This index type specifies that the column is a primary key. The values in this column cannot be NULL.
  • UniqueKey – This index type specifies that the column is a unique key. Any values in this column may also be NULL Currently, this only creates individual keys as opposed to composite unique keys.
The index types below are only usable with halfvec and vector column types, and require the pgvector extension to be installed.
  • HNSW[L2] – This index type is an implementation of Hierarchical Navigable Small World graphs using Euclidean (L2) distance as the distance metric.

  • HNSW[Cosine] – This index type is an implementation of Hierarchical Navigable Small World graphs using cosine distance as the distance metric.

  • HNSW[InnerProduct] – This index type is an implementation of Hierarchical Navigable Small World graphs using inner product (dot product) as the distance metric.

  • IVFFlat[L2] – This index type is an implementation of Inverted File with Flat compression using Euclidean (L2) distance as the distance metric.

  • IVFFlat[Cosine] – This index type is an implementation of Inverted File with Flat compression using cosine distance as the distance metric.

  • IVFFlat[InnerProduct] – This index type is an implementation of Inverted File with Flat compression using inner product (dot product) as the distance metric.

Geometry Definition

In formats that support reading or controlling the writing of geometric (spatial) data, a Geometry Definition table is visible in the User Attributes tab of a feature type.

For more information, see: