Description Objects from the Class Slots Extends Methods Author(s) See Also Examples
An object of this class points to a real table/view in the database. No data is transfered into R. Only a minimal amount of information is kept in the object.
Objects can be created by calls of db.data.frame
or
as.db.data.frame
.
The object represents a real table/view in the database. Usually it is NOT recommended to directly manipulate the internal slots of these objects.
.name
:Object of class "character"
. It is the table name if this
db.data.frame
was created using just a table name. It can
also be a two-element array if this db.data.frame
was
created. This slot is obsolete.
.content
:Object of class "character"
. The table
name. The function content
can get this value.
.conn.id
:Object of class "numeric"
, an integer. The ID number of the
database
connection where the table resides. The functions
conn.id
and conn.id<-
can get and set
this value.
.col.name
:Object of class "character"
. The 1D array of column names
of the table/view that this db.data.frame
points to. The
S4 method names,db.obj-method
gets this value.
.col.data_type
:Object of class "character"
. The 1D array of column data
types of the table/view that this db.data.frame
points
to. This is not supposed to be used by the normal user.
.col.udt_name
:Object of class "character"
. The 1D array of column udt
names of
the table/view that this db.data.frame
points to. This is
not to used by normal users.
.table.type
:Object of class "character"
. The information about the type
of tha table/view that this db.data.frame
points
to, for example, "BASE TABLE", "VIEW" or "LOCAL TEMPORARY".
.is.factor
:Object of class "logical"
. An array of logical values which
indicate whether each column of the table/view is a factor. This
is not to be used by the normal users.
.factor.suffix
:Object of class "character"
. An array of strings for
every column. When creating dummy columns
for a factor column, we add a random string in the names of the
dummy columns to avoid naming conflicts. So a factor column's
.factor.suffix
is a random string, otherwise it is just an
empty string. This is not to be used by the normal users. It is
used only the MADlib wrapper functions that support categorical
variables.
.factor.ref
:The value of the factor reference level for the regressions. If it is NA
, then the regressions automatically select a reference level.
.appear.name
:Object of class "character"
. This
is also related the factor columns. print.lm.madlib
and
print.logregr.madlib
use this value for printing the
names of the dummy columns. This is not to be used by the normal users.
.dummy
:Object of class "character"
. An array of strings,
The dummy column names which are
used only for factor support.
.dummy.expr
:Object of class "character"
. The SQL expressions used to
create dummy column names which are
used only for factor support.
.dist.by
:A string, the distribution policy when using Greenplum database or HAWQ. It can be character(0)
, which means the data table is distributed randomly. Or it can be a string of column names separated by comma, which are the columns that are used in the "distributed by" when the table was created.
Class db.obj
, directly.
Aggregate functions
, by,db.obj-method
,
dim,db.table-method
, dim,db.view-method
,
dim,db.Rquery-method
, names,db.obj-method
,
conn.id
, conn.id<-
,
eql
, key
, key<-
,
merge,db.obj,db.obj-method
,
print,db.data.frame-method
,
show,db.data.frame-method
,
sort,db.obj-method
, subset,db.obj-method
,
Arith methods
, Compare methods
,
Logical methods
, Extraction methods
,
Replacement methods
, madlib.lm
,
madlib.glm
, madlib.summary
Author: Predictive Analytics Team at Pivotal Inc.
Maintainer: Frank McQuillan, Pivotal Inc. fmcquillan@pivotal.io
db.data.frame
creates a db.data.frame
object.
as.db.data.frame
converts db.Rquery
object,
data.frame
, or a data file into a db.data.frame
object
and at the same time creates a new table in the database.
db.obj
is the superclass.
db.table
and db.view
are the
sub-classes.
db.Rquery
is another sub-class of
db.obj
.
lk
or lookat
display a part of the table
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | ## Not run:
showClass("db.data.frame")
## set up the database connection
## Assume that .port is port number and .dbname is the database name
cid <- db.connect(port = .port, dbname = .dbname, verbose = FALSE)
delete("abalone", conn.id = cid)
as.db.data.frame(abalone, "abalone", conn.id = cid, verbose = FALSE)
x <- db.data.frame("abalone", conn.id = cid, verbose = FALSE) # x points to table "abalone"
lk(x)
db.disconnect(cid, verbose = FALSE)
## End(Not run)
|
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