table cf create
Creates a column family for a MapR binary or JSON table.
Syntax
- CLI
-
maprcli table cf create -path Table path -cfname Column family name [ -minversions Min versions to keep. default: 0 ] [ -maxversions Max versions to keep. default: 1 ] [ -ttl Time to live. Enter 0 for forever. Otherwise enter time in seconds. default: 0 ] [ -inmemory In-memory. default: false ] [ -compression off|lzf|lz4|zlib. default: table's compression setting is applied. ] [ -versionperm Version Permissions ] [ -compressionperm Compression Permissions ] [ -memoryperm Memory Permissions ] [ -readperm Read Permissions ] [ -writeperm Write Permissions ] [ -appendperm Append Permissions ] [ -jsonpath Json Family Path - needed for JSON column family, like a.b.c ] [ -force Force create non-default column family for json tabletype. default: false ] [ -traverseperm Traverse Permissions ]
- REST
-
http[s]://<host>:<port>/rest/table/cf/create?path=<path>&cfname=<name>&<parameters>
mapr
user is not treated as a superuser.
MapR-DB does not allow the mapr
user to run this command unless that user
is given the relevant permission or permissions with access-control expressions.Parameters
Parameter |
Description |
---|---|
path |
The path to the table.
|
cfname |
The name of the column family to create. |
minversions | Applies to binary tables only: Minimum number of versions of column values to keep. The default is zero. |
maxversions | Applies to binary tables only: Maximum number of versions of column values to keep. The default is one. |
ttl | Time to live in seconds. The default value is forever .
When the age of the data in this column family exceeds the value of the
ttl parameter, the data is purged. Setting the value of
ttl to 0 is equivalent to the default value of
forever .NOTE: If the value of -ttl for an existing
column family in a JSON table is not 0, you
cannot add another column family. See Setting TTL for Data in JSON Tables. |
inmemory |
Boolean. Determines whether preference is given to values of this column family for storage with row keys. Because row keys are cached in memory in preference to row data, column-family data that is stored inline with the row keys is also cached in memory. For all column families in a table together, up to 200 bytes of row data
will be stored inline with each row key. Storing data inline with a row
key might speed retrieval of the data from a column family because disk
access can often be avoided. For each column family, up to 32 bytes can
be stored inline with each row key even if its If the total number of bytes for all column families together exceeds 200
for a row, then preference for inclusion within the inline storage for
that row is given to column families that have the
NOTE: All of the data for a column family will be stored in-line with the
row key, or none will be. If the contents in a column family for a
particular row are larger than the maximum number of bytes that are
allowed to be stored for that column family, no data at all will be
stored in-line for that column family.
The default value for the |
compression | Applies to binary tables only:
The compression setting to use for the column family. Valid options are
off , lzf , lz4 , and
zlib . The default setting is equal to the table's
compression setting. For more information, see Compression. |
versionperm | Applies to binary tables only:
The Access Control Expression for changing the value of the
maxversions and minversions parameters.
By default, permission is given to the value of
defaultversionperm for the table. |
compressionperm | Applies to binary tables only:
The Access Control Expression for changing the value of the
compression parameter. By default, permission is given
to the value of defaultcompressionperm for the
table. |
memoryperm | The Access Control Expression for changing the value of the
inmemory parameter. Use single quotation marks around
the ACE. By default, permission is given to the value of
defaultmemoryperm for the table. |
readperm |
The Access Control Expression for column reads. Use single quotation marks around the ACE. Reads require permission both at the column-family level and at the column level (for binary tables) or field level (for JSON tables). In JSON tables, this permission is inherited by fields within the column family. By default, permission is given to the value of
|
writeperm |
The Access Control Expression for column writes (puts and deletes). Use single quotation marks around the ACE. Writes require permission both at the column-family level and at the column level (for binary tables) or field level (for JSON tables). In JSON tables, this permission is inherited by fields within the column family. By default, permission is given to the value of
|
appendperm |
Applies to binary tables only: The Access Control Expression for column appends. Use single quotation marks around the ACE. Column appends require permission both at the column-family level and at
the column level. By default, permission is given to the value of
|
jsonpath |
Applies to JSON tables
only: Specifies the path to the column family. The
path is in dotted notation. For example, suppose the table contained JSON
documents that were of this general structure:
You want to create a column family at the field d
in the new path a.b.d because you plan to store image
files in fields in that column family. IMPORTANT: Ensure that the field at which you want to create the column
family does not yet exist. If the field does exist, it could become inaccessible
after the column family is created. |
force | Applies to JSON tables only: By default, every time you try to create a non-default column family in a JSON table, this command fails and returns a warning message that you should ensure there is no existing data at the specified path. Set this parameter to true if you want to override this warning mechanism and create a column family. |
traverseperm |
Applies to JSON tables only: The Access Control
Expressions that specifies who has permission to pass over fields in JSON
documents. For example, suppose that a JSON table contains documents of this
general structure:
Suppose
further that the user sjohnson has read permission on
a.b , but not on a . For sjohnson to
read a.b , the user needs the traverse permission on
a . The user can then pass over field a to
a.b . This permission is inherited by fields within the column family. By default, this permission is given to the value of defaulttraverseperm for the JSON table. |
Examples
Creating a new column family for a table, keeping four versions in memory- CLI
-
maprcli table cf create -path /volume1/mytable -cfname mynewcf -maxversions 4 -inmemory true
- REST
-
https://r1n1.sj.us:8443/rest/table/cf/create?path=%2Fvolume1%2Fmytable&cfname=mynewcf&maxversions=4&inmemory=true