Example 2-17 Merging Ordered and Unordered ore.frame Objects

# Prepare the data.
library(kernlab)
data(spam)
s <- spam
# Create a column that has integer values.
s$TS <- 1001:(1000 + nrow(s))
# Create a column that has integer values with each number repeated twice.
s$USERID <- rep(351:400, each=2, len=nrow(s))
# Ensure that the database tables do not exist.
ore.drop(table='SPAM_PK')
ore.drop(table='SPAM_NOPK')
# Create database tables.
ore.create(s[,c(59:60,1:28)], table="SPAM_PK")
ore.create(s[,c(59:60,1:28)], table="SPAM_NOPK")
# Using a SQL statement, alter the SPAM_PK table to add a composite primary key.
ore.exec("alter table SPAM_PK add constraint SPAM_PK primary key
           (\"USERID\",\"TS\")")
# Synchronize the table to get the change to it.
ore.sync(table = "SPAM_PK")
# Create objects for merging data from unordered ore.frame objects.
x <- SPAM_NOPK[,1:4]
y <- SPAM_NOPK[,c(1,2,4,5)]
m1 <- merge(x, y, by="USERID")
# The merged result m1 produces a warning because it is not an ordered frame.
head(m1,3)
# Create objects for merging data from ordered ore.frame objects.
x <- SPAM_PK[,1:4]
y <- SPAM_PK[,c(1,2,4,5)]
# The merged result m1 does not produce a warning now because it is an 
# ordered frame.
m1 <- merge(x, y, by="USERID")
head(m1,3)

R> # Prepare the data.
R> library(kernlab)
R> data(spam)
R> s <- spam
R> # Create a column that has integer values.
R> s$TS <- 1001:(1000 + nrow(s))
R> # Create a column that has integer values with each number repeated twice.
R> s$USERID <- rep(351:400, each=2, len=nrow(s))
R> # Ensure that the database tables do not exist.
R> ore.drop(table='SPAM_PK')
R> ore.drop(table='SPAM_NOPK')
R> # Create database tables.
R> ore.create(s[,c(59:60,1:28)], table="SPAM_PK")
R> ore.create(s[,c(59:60,1:28)], table="SPAM_NOPK")
R> # Uing a SQL statement, alter the SPAM_PK table to add a composite primary key.
R> ore.exec("alter table SPAM_PK add constraint SPAM_PK primary key
+          (\"USERID\",\"TS\")")
R> # Synchronize the table to get the change to it.
R> ore.sync(table = "SPAM_PK")
R> # Create objects for merging data from unordered ore.frame objects.
R> x <- SPAM_NOPK[,1:4]
R> y <- SPAM_NOPK[,c(1,2,4,5)]
R> m1 <- merge(x, y, by="USERID")
R> # The merged result m1 produces a warning because it is not an ordered frame.
R> head(m1,3)
  USERID TS.x make address.x TS.y address.y  all
1    351 5601 0.00         0 1001      0.64 0.64
2    351 5502 0.00         0 1001      0.64 0.64
3    351 5501 0.78         0 1001      0.64 0.64
Warning messages:
1: ORE object has no unique key - using random order 
2: ORE object has no unique key - using random order
R> # Create objects for merging data from ordered ore.frame objects.
R> x <- SPAM_PK[,1:4]
R> y <- SPAM_PK[,c(1,2,4,5)]
R> # The merged result m1 does not produce a warning now because it is an 
R> # ordered frame.
R> m1 <- merge(x, y, by="USERID")
R> head(m1,3)
          USERID TS.x make address.x TS.y address.y  all
1001|1001    351 1001    0      0.64 1001      0.64 0.64
1001|1002    351 1001    0      0.64 1002      0.28 0.50
1001|1101    351 1001    0      0.64 1101      0.00 0.00