Re: MonetDB Blob Inserts

Hi Sjoerd,

I don't quite understand why do we need to convert original binary into hex string - that takes extra time for conversion and [even worse] appears to double the size of the original binary data...

p.s. I developed BLOBimport C UDF that takes as input already existing Monet table and outputs Monet blob table [by converting its original table columns from Monet binary to our in-house binary data format].

sql_column *col1 = mvc_bind_column(m, blob_tbl, "v_blob"); char *data; size_t blob_len = reclen; BAT *tmp1 = COLnew(0, TYPE_sqlblob, (BUN)nrow, TRANSIENT); blob *ele_blob; ele_blob = GDKmalloc(blobsize(reclen)); ele_blob->nitems = reclen; jda = 0;

for (irow=0; irow < nrow; irow++) { memcpy(ele_blob->data, &da[jda], blob_len); //char *da contains original binary data records [with fixed length] BUNappend(tmp1, ele_blob, FALSE); jda += reclen; } mvc_append_column(m->session->tr, col1, tmp1); mvc_commit(m, 0, tr->name); bat_destroy(tmp1);

Also I developed another C UDF BLOBexport that takes blob table as input and creates [in-house binary data format] output file.

Thanks, Anton

On Fri, Sep 15, 2017 at 8:00 AM, Anton Kravchenko < kravchenko.anton86@gmail.com> wrote:

great, thanks!

On Fri, Sep 15, 2017 at 1:28 AM, Sjoerd Mullender sjoerd@acm.org wrote:

...

On 15/09/17 06:25, Anton Kravchenko wrote:

...

Hi Sjoerd,

Does MonetDB support BINARY BULK LOAD into a blob column? And if not, is there a reason?

Yes it does:

create table t (i int, b blob, s clob); copy 1 records into t from stdin; 10|0102030405060708090a0b0c0d0e0f|string select * from t;

You can of course use different delimiters, copy from an external file, etc.

...

Thanks, Anton

On Sat, Jul 8, 2017 at 9:02 PM, Brian Hood <brianh6854@googlemail.com mailto:brianh6854@googlemail.com> wrote:

Hi Sjoerd,

Thank you for this is makes sense now.

However essentially to INSERT data into a BLOB you are going to have
convert the data before inserting it into database, which could be
expensive in compute time.

Regards,

Brian Hood

On Mon, Jun 26, 2017 at 9:19 AM, Sjoerd Mullender <sjoerd@acm.org
<mailto:sjoerd@acm.org>> wrote:

    On 24/06/17 21:31, Brian Hood wrote:
    > Hi Guys,
    >
    > I don't seem to be able to INSERT into a blob field is there

any

...

    > information how to achieve this.
    >
    > Regards,
    >
    > Brian Hood
    > _______________________________________________
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    <https://www.monetdb.org/mailman/listinfo/users-list>
    >

    Normally that would be something like:
    INSERT INTO t VALUES ('0102030405060708090a0b0c0d0e0f');
    where the value being inserted is no more than a list of

hexadecimal

...

    digits with en even length (two digits per octet).

    --
    Sjoerd Mullender


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