# SYS_SPATIAL_SIMPLIFY

You can query the system view SYS_SPATIAL_SIMPLIFY to get information about simplified
spatial geometry objects using the COPY command. When you use COPY on a shapefile, you
can specify SIMPLIFY `tolerance`

, SIMPLIFY AUTO, and SIMPLIFY AUTO
`max_tolerance`

ingestion options. The result of the simplification is
summarized in SYS_SPATIAL_SIMPLIFY system view.

When SIMPLIFY AUTO `max_tolerance`

is set, this view contains a row for
each geometry that exceeded the maximum size. When SIMPLIFY `tolerance`

is
set, then one row for the entire COPY operation is stored. This row references the COPY
query ID and the specified simplification tolerance.

For more information about loading a shapefile, see Loading a shapefile into Amazon Redshift.

SYS_SPATIAL_SIMPLIFY is visible to all users. Superusers can see all rows; regular users can see only their own data. For more information, see Visibility of data in system tables and views.

## Table columns

Column name | Data type | Description |
---|---|---|

query_id | bigint | The ID of the query (COPY command) that generated this row. |

line_number | bigint | When COPY `SIMPLIFY AUTO` option is
specified, this value is the record number of the simplified record
in the shapefile. |

maximum_tolerance | double precision | The distance tolerance value specified in the COPY command.
This is either the maximum tolerance value using the `SIMPLIFY AUTO` option,
or the fixed tolerance value using the `SIMPLIFY` option. |

initial_size | bigint | The size in bytes of the `GEOMETRY`
data value before simplification. |

simplified | char(1) | When the COPY `SIMPLIFY AUTO` option is
specified, `t` if the geometry was successfully
simplified, or `f` otherwise. The geometry might not be
simplified successfully if after the simplification with the given
maximum tolerance its size is still larger than the maximum geometry
size. |

final_size | bigint | When the COPY `SIMPLIFY AUTO` option is
specified, this is the size in bytes of the geometry after
simplification. |

final_tolerance | double precision | Final tolerance chosen for the simplification. |

## Sample query

The following query returns the list of records that COPY simplified.

`SELECT * FROM sys_spatial_simplify;`

`query_id | line_number | maximum_tolerance | initial_size | simplified | final_size | final_tolerance ----------+-------------+-------------------+--------------+------------+------------+---------------------- 20 | 1184704 | -1 | 1513736 | t | 1008808 | 1.276386653895e-05 20 | 1664115 | -1 | 1233456 | t | 1023584 | 6.11707814796635e-06`