I have some data in Hive 1.2.1 table. I have to get raw bytes of a specific column. The column data is html raw in multiple languages. In order to get length of characters, I can use simple query like below
select baseurl, LENGTH(content) from clss limit 30;
Above query is ok for characters length the problem is for text other is English, their value is incorrect. For a Character in Arabic, it is saved as unicoded that's why character length is changed. Some characters are of two bytes and some are single byte.
Is there any builtin function to know bytes of text instead of characters ?
Function character_length(string str) was added in Jira HIVE-15979 And it says Fix versions 2.3.0. If you cannot upgrade your Hive (and this is quite risky), then try to download UDF source codes and build it, then add jar and create temporary function.
Download code: GenericUDFCharacterLength.java
Related
Prehistory: Hello, i saw many questions about encoding in postgres, but.
I have UFT8 table, and i'm using COPY function to import that table in CSV, and i need to make COPY with different encodings like WIN1251 and SQL_ASCII.
Problem: When in table i have characters that not supported in WIN1251/SQL_ASCII, i will got classic error
character with byte sequence 0xe7 0xb0 0xab in encoding "UTF8" has no equivalent in encoding "WIN1251"
I tried using "set client_encoding/ convert / convert_to" - no success.
Main question: Is there any way to do this without error using sql?
There is simply no way to convert 簫 into Windows-1252, so you can forget about that.
If you set the client encoding to SQL_ASCII, you will be able to load the data into an SQL_ASCII database, but that is of little use, since the database does not recognize it as a character, but three meaningless bytes above 127.
I'm querying some tables on Athena (Presto SAS) and then downloading the generated CSV file to use locally. Opening the file, I realised the data contains new line characters that doesn't appear on AWS interface, only in the CSV and need to get rid of them. Tried using the function replace(string, search, replace) → varchar to skip the newline char replacing \n for \\n without success:
SELECT
p.recvepoch, replace(p.description, '\n', '\\n') AS description
FROM
product p
LIMIT 1000
How can I achieve that?
The problem was that the underlying table data doesn't actually contains \n anywhere, instead, the actual newline character, which is represented by char(10). I was able to achieve the expected behaviour using the replace function passing it as parameter:
SELECT
p.recvepoch, replace(p.description, chr(10), '\n') AS description
FROM
product p
LIMIT 1000
Kind of a strange question, but I'm doing some testing to handle errors when a dicom file's tags can't be read.
Unfortunately I don't have a damaged dicom available.
Specifically, can anyone advise how to apply some sort of incorrectly encoded text tag or some invalid numeric data tag onto the file, such that it can't be read by python's pydicom package?
you could have a look at the dcmodify tool from the DCMTK. It can be used to insert, modify and delete attributes. I doubt that it is possible to specify invalid attribute values through the command line, but you could surely modify the source code to accomplish that (except you can definitely write attribute values that exceed the maximum length according to the Value Representation).
My approach would be to create a buffer of characters and write binary data to it. Then pass it to the method that writes the value to the attribute.
Examples:
write unicode (UTF-8) sequences which are not a valid unicode character
write ascii characters which are not covered by the characterset specified by (0008,0005) - not sure whether pydicom would run into problems but it would be wrong from the DICOM perspective
write non-numeric characters to attributes with Value Representation "Decimal String" or "Integer String".
formats other than YYYYMMDD for VR "Date"
formats other than HHMMSS.FFFFFF for VR "Time"
other characters than ['0'-'9'], '.' for VR "Unique Identifier"
[edit]: DCMTK, dcmodify: http://dicom.offis.de/dcmtk.php.en
In pig script, I would like to find a way to escape the delimiter character in my data so that it doesn't get interpreted as extra columns. For example, if I'm using colon as a delimiter, and I have a column with value "foo:bar" I want that string interpreted as a single column without having the loader pick up the comma in the middle.
You can try http://pig.apache.org/docs/r0.12.0/func.html#regex-extract-all
A = LOAD 'somefile' AS (s:chararray);
B = FOREACH A GENERATE FLATTEN(REGEX_EXTRACT_ALL(s, '(.*) : (.*)'));
The regex might have to be adapted.
It seems Pig takes the Input as the string its not so intelligent to identify how what is data or what is not.
The pig Storage works on the Strong Tokenizer. So if u want to do something like
a = LOAD '/abc/def/file.txt' USING PigStorage(':');
It doesn't seems to be solving your problem. But if we can write our own PigStorage() Method possibly we could come across some solution.
I will try posting the Code to resolve this.
you can use STRSPLIT(string, regex, limit); for the column split based on the delimiter.
What is causing the two fields to be different ? Is it a tab or something else ? What is an easy way to clean it ? I know I can somehow use replace, but I am unsure of what I am replacing and there are many more records with the same problem.
Name Binary
MCMPAD 0x4D0043004D00500041004400200020
MCMPAD 0x4D0043004D00500041004400A00020
SELECT Name , convert(binary(15), (Name)) Binary from VirtualTerminal
where Name like '%MCMPAD%'
One string ends with space-space 0x2020, the other with linefeed-space 0x0A20. The difference is not visible when you display Name as a string.
The extra zeroes (space is 0x0020 instead of 0x20) are for the Windows standard UCS-2 encoding.