By default, Avro doesn't support timestamp but I can have 'Epoch' time values having 'Long' type in the file. What I want is to load those values in 'Timestamp' format while loading the Avro file data to Bigquery table using command line tool.
For example : I have a column having value 1511253927 and I want this value to be loaded as 2017-11-21 00:00:00 using command line tool.
Any leads will be appreciated.
You can try to run a query with your file as a federated data source and use TIMESTAMP_SECONDS standard SQL function to convert values.
Related
I'm trying to import CSV files into BigQuery and on any of the hourly reports I attempt to upload it gives the code
Error while reading data, error message: Could not parse 4/12/2016 12:00:00 AM as TIMESTAMP for field SleepDay (position 1) starting at location 65 with message Invalid time zone: AM
I get that the format is trying to use AM as a timezone and causing an error but I'm not sure how best to work around it. All of the hourly entries will have AM or PM after the date-time and that will be thousands of entries.
I'm using the autodetect for my schema and I believe that's where the issue is coming up, but I'm not sure what to put in the edit as text schema option to fix it
To successfully parse an imported string to timestamp in Bigquery, the string must be in the ISO 8601 format.
YYYY-MM-DDThh:mm:ss.sss
If your source data is not available in this format, then try the below approach.
Import the CSV into a temporary table by providing explicit schema, where timestamp fields are strings.
2. Select the data from the created temporary table, use the BigQuery PARSE_TIMESTAMP function as specified below and write to the permanent table.
INSERT INTO `example_project.example_dataset.permanent_table`
SELECT
PARSE_TIMESTAMP('%m/%d/%Y %H:%M:%S %p',time_stamp) as time_stamp,
value
FROM `example_project.example_dataset.temporary_table`;
When I load parquet files into Bigquery table, values stored are wierd. It seems to be the encoding of BYTES fields or whatever else.
Here's the format of the create fields
So when I read the table with casted fields, I get the readable values.
I found the solution here
Ma question is WHY TF bigquery is bahaving like this?
According to this GCP documentation, there are some parquet data types that can be converted into multiple BigQuery data types. A workaround is to add the data type that you want to parse to BigQuery.
For example, to convert the Parquet INT32 data type to the BigQuery DATE data type, specify the following:
optional int32 date_col (DATE);
And another way is to add the schema to the bq load command:
bq load --source_format=PARQUET --noreplace --noautodetect --parquet_enum_as_string=true --decimal_target_types=STRING [project]:[dataset].[tables] gs://[bucket]/[file].parquet Column_name:Data_type
I have a script that downloads data from an Oracle database, and uploads it to Google BigQuery. This is done by writing to an Avro file, which is then uploaded directly using BQ's python framework. The BigQuery tables I'm uploading the data to has predefined schemas, some of which contain DATETIME fields.
As BigQuery now has support for Avro Logical fields, import of timestamp data is no longer a problem. However, I'm still not able to import datetime fields. I tried using string, but then I got the following error:
Field CHANGED has incompatible types. Configured schema: datetime; Avro file: string.
I also tried to convert the field data to timestamps on export, but that produced an internal error in BigQuery:
An internal error occurred and the request could not be completed. Error: 3144498
Is it even possible to import datetime fields using Avro?
In Avro, the logical data types must include the attribute logicalType, it is possible that this field is not included in your schema definition.
Here there are a couple of examples like the following one. As far as I know the type can be int or long, but logicalType should be date:
{
'name': 'DateField',
'type': 'int',
'logicalType': 'date'
}
Once the logical data type is set, try again. The documentation does indicate it should work:
Avro logical type --> date
Converted BigQuery data type --> DATE
In case you get an error, it would be helpful to check the schema of your avro file, you can use this command to obtain its details:
java -jaravro-tools-1.9.2.jargetschema my-avro-file.avro
UPDATE
For cases where DATE alone doesn't work, please consider that the TIMESTAMP can store the date and time with a number of micro/nano seconds from the unix epoch, 1 January 1970 00:00:00.000000 UTC (UTC seems to be the default for avro). Additionally, the values stored in an avro file (of type DATE o TIMESTAMP) are independent of a particular time zone, in this sense, it is very similar to BigQuery Timestamp data type.
When we create an ORC table in hive we can see that the data is compressed and not exactly readable in HDFS. So how is Hive able to convert that compressed data into readable format which is shown to us when we fire a simple select * query to that table?
Thanks for suggestions!!
By using ORCserde while creating table. u have to provide package name for serde class.
ROW FORMAT ''.
What serde does is to serialize a particular format data into object which hive can process and then deserialize to store it back in hdfs.
Hive uses “Serde” (Serialization DeSerialization) to do that. When you create a table you mention the file format ex: in your case It’s ORC “STORED AS ORC” , right. Hive uses the ORC library(Jar file) internally to convert into a readable format. To know more about hive internals search for “Hive Serde” and you will know how the data is converted to object and vice-versa.
I'm trying to load data from Oracle to Hive as parquet. Every time i load a table with date/timestamp column to hive, it automatically converts these columns to BIGINT. Is is possible to load timestamp/date formats to hive using sqoop and as a parquet file?
Already tried creating the table first in hive then using impala to LOAD DATA INPATH the parquet file.
Still failed with errors
"file XX has an incompatible Parquet schema for column XX column:
TIMESTAMP"
BTW, I'm using cloudera quickstart vm. Thanks
From the Cloudera documentation:
If you use Sqoop to convert RDBMS data to Parquet, be careful with interpreting any resulting values from DATE, DATETIME, or TIMESTAMP columns. The underlying values are represented as the Parquet INT64 type, which is represented as BIGINT in the Impala table. The Parquet values represent the time in milliseconds, while Impala interprets BIGINT as the time in seconds. Therefore, if you have a BIGINT column in a Parquet table that was imported this way from Sqoop, divide the values by 1000 when interpreting as the TIMESTAMP type.
Or you can also use your Hive query like this to get the result in your desired TIMESTAMP format.
FROM_UNIXTIME(CAST(SUBSTR(timestamp_column, 1,10) AS INT)) AS timestamp_column;
Try using configuration of sqoop
--map-column-hive
<cols_name>=TIMESTAMP