RODBC does not save greater than 8k varchar/text from a data frame

Question

I am scraping web data and some results are more than 8K of text. I have a field in my MS SQL Server 2008 R2 that is varchar(max) but RODBC only saves 8K and truncates the rest. I have DSN connections set up using both SQL Native Client 10 from SS R2 and ODBC 11.

sqlType returns -1 for the field title, indicating varchar(max)/text.

Both connections truncate the text at 8K. Is there a fix/workaround for this or am I limited to 8K in SQL Server? I can switch to MySQL if the R mySQL driver will pass the larger amounts of text through. I'm using R 3.0.1 and RODBC 1.3-6 on Win 7 x64.

Here is some sample code to replicate the problem.

CREATE TABLE
[test](
[title] [varchar](max) NULL
) ON [PRIMARY]


library(RODBC)
ch <- odbcConnect("text", uid = "X", pwd = "X")
sqlTypeInfo(ch,"test")

testtext = data.frame("salasjflsjsf")
colnames(testtext) = "title"

## This works
sqlSave(ch,testtext,"test",append=TRUE, rownames=FALSE, colnames = FALSE, safer=FALSE,  verbose = TRUE)


## text > 8K
testtext = data.frame(paste(rep("salasjflsjsf",5000),collapse=""))
colnames(testtext) = "title"

## use ODBC default type for title
sqlSave(ch,testtext,"test",append=TRUE, rownames=FALSE, colnames = FALSE, safer=FALSE,  verbose = TRUE)

## this message from ODBC
## Query: INSERT INTO "test" ( "title" ) VALUES ( ? )
## Binding: 'title' DataType 12, ColSize 8000
## Parameters:
## no: 1: title salasjfl
## [*text removed*]
## lsjsfsalasjflsjsfsalasjflsjsfsalasjflsjsfsalasjflsjsfsalasjflsjsfsalasjflsjsf/***/
## Warning message:
## In odbcUpdate(channel, query, mydata, coldata[m, ], test = test,  :
##   character data 'salasjflsjsfsalasjflsjsfsalasjflsjsfsalasjfl




## try with varType set to text
sqlSave(ch,testtext,"test",append=TRUE, varType = "text",rownames=FALSE, colnames = FALSE, safer=FALSE,  verbose = TRUE)

## try with varType set to varchar(MAX)
sqlSave(ch,testtext,"test",append=TRUE, varType = "varchar(max)",rownames=FALSE, colnames = FALSE, safer=FALSE,  verbose = TRUE)

close(ch)

I changed the column type to text and refreshed the DSN connection. Text type is being picked up but now there is an error message:

 chtest <-odbcConnect("test2", uid = "X", pwd = "X")
    > sqlColumns(chtest,"test")
      TABLE_CAT TABLE_SCHEM TABLE_NAME COLUMN_NAME DATA_TYPE TYPE_NAME COLUMN_SIZE BUFFER_LENGTH DECIMAL_DIGITS NUM_PREC_RADIX NULLABLE REMARKS
    1   RSS            dbo       test       title        -1      text  2147483647    2147483647             NA             NA        1    <NA>
      COLUMN_DEF SQL_DATA_TYPE SQL_DATETIME_SUB CHAR_OCTET_LENGTH ORDINAL_POSITION IS_NULLABLE SS_IS_SPARSE SS_IS_COLUMN_SET SS_IS_COMPUTED
    1       <NA>            -1               NA        2147483647                1         YES            0                0              0
      SS_IS_IDENTITY SS_UDT_CATALOG_NAME SS_UDT_SCHEMA_NAME SS_UDT_ASSEMBLY_TYPE_NAME SS_XML_SCHEMACOLLECTION_CATALOG_NAME
    1              0                <NA>               <NA>                      <NA>                                 <NA>
      SS_XML_SCHEMACOLLECTION_SCHEMA_NAME SS_XML_SCHEMACOLLECTION_NAME SS_DATA_TYPE
    1                                <NA>                         <NA>           35
    > sqlSave(chtest,testtext,"test",append=TRUE, varType = "text",rownames=FALSE, colnames = FALSE, safer=FALSE,  verbose = TRUE)
    Query: INSERT INTO "test" ( "title" ) VALUES ( ? )
    Binding: 'title' DataType -1, ColSize 2147483647
    Error in odbcUpdate(channel, query, mydata, coldata[m, ], test = test,  : 
      'Calloc' could not allocate memory (18446744071562067968 of 1 bytes)
    In addition: Warning messages:
    1: In odbcUpdate(channel, query, mydata, coldata[m, ], test = test,  :
      Reached total allocation of 6013Mb: see help(memory.size)
    2: In odbcUpdate(channel, query, mydata, coldata[m, ], test = test,  :
      Reached total allocation of 6013Mb: see help(memory.size)

Answer 1

You defined the text column to be of type varchar(max), so it will be stored that way, regardless of specifying varType when saving the data.

Try creating a table with a TEXT column instead, then using sqlSave. This way the data will be stored out of row context and you'll shouldn't have the truncation issue.