2.2.5.5 Getting Information about Datastore Contents

You can get information about a datastore in the current user schema by using the ore.datastore and ore.datastoreSummary functions.

Using the ore.datastore function, you can list basic information about datastores. To get information about a specific type of datastore, you can use the optional character string type argument. The valid values for typeare the following:

  • user, which lists the datastores created by current session user. This is the default value.

  • private, which lists the datastores for which read access cannot be granted by the current session user to other users.

  • all, which lists all of the datastores to which the current session user has read access.

  • grantable, which lists the datastores the read privilege for which can be granted by the current session user to other users.

  • grant, which lists the datastores the read privilege for which has been granted by the current session user to other users.

  • granted, which lists the datastores the read privilege for which has been granted by other users to the current session user.

If you do not specify a type, then function ore.datastore returns a data.frame object with columns that correspond to the datastore name, the number of objects in the datastore, the datastore size, the creation date, and a description. Rows are sorted by column datastore.name in alphabetical order. If you do specify a type, then the function returns a data.framethat has a column for the specified type.

You can search for a datastore by name or by using a regular expression pattern.

The ore.datastoreSummary function returns information about the R objects saved within a datastore in the user schema in the connected database. The function returns a data.frame with columns that correspond to object name, object class, object size, and either the length of the object, if it is a vector, or the number of rows and columns, if it is a data.frame object. It takes one required argument, the name of a datastore, and has an optional argument, the owner of the datastore.

Example 2-20 Using the ore.datastore Function

This example demonstrates using the ore.datastore function. The example uses some of the R objects created in Example 2-18.

# The datastore objects ds1 and ds2 and objects data.frame objects df1 and df2
# were created in Example 2-18.
ore.save(df1, df2, name = "dfobj", description = "df objects"
ore.save(x, y, z, name = "another_ds", description = "For pattern matching")

# List all of the datastore objects.
ore.datastore()

# List the specified datastore.
ore.datastore("ds1")

# List the datastore objects with names that include "ds".
ore.datastore(pattern = "ds")
Listing for Example 2-20
R> # The datastore objects ds1 and ds2 and objects data.frame objects df1 and df2
R> # were created in Example 2-18.
R> ore.save(df1, df2, name = "dfobj", description = "df objects"
R> ore.save(x, y, z, name = "another_ds", description = "For pattern matching")
R> 
R> # List all of the datastore objects.
R> ore.datastore()
  datastore.name object.count size       creation.date  description
1     another_ds            3 1243 2014-07-24 13:31:56 For pattern mattching
2          dfobj            2  656 2014-07-24 13:31:46            df objects
3            ds1            4 3162 2014-07-24 13:25:17          My datastore
4            ds2            2 1111 2014-07-24 13:27:26                only x

R> # List the specified datastore.
R> ore.datastore("ds1")
  datastore.name object.count size       creation.date  description
1            ds1            4 2908 2013-11-08 10:41:09 My datastore
R> 
R> # List the datastore objects with names that include "ds".
R> ore.datastore(pattern = "ds")
  datastore.name object.count size       creation.date            description
1     another_ds            3 1243 2014-07-24 13:31:56  For pattern mattching
2            ds1            4 3162 2014-07-24 13:25:17           My datastore
3            ds2            2 1111 2014-07-24 13:27:26                 only x

Example 2-21 Using the ore.datastoreSummary Function

This example demonstrates using the ore.datastoreSummary function. The example uses the datastores created in Example 2-18.

ore.datastoreSummary("ds1")
ore.datastoreSummary("ds2")
Listing for Example 2-21
R> ore.datastoreSummary("ds1")
    object.name      class size length row.count col.count
1    AIRQUALITY  ore.frame 1077      6       153         6
2           df1 data.frame  328      2         5         2
3           df2 data.frame  328      2         5         2
4       iris_of  ore.frame 1429      5       150         5
R> ore.datastoreSummary("ds2")
  object.name       class size length row.count col.count
1           x     numeric  182     20        NA        NA
2           z ore.numeric  929     20        NA        NA