Meta Integration® Model Bridge (MIMB)
"Metadata Integration" Solution

MIMB Bridge Documentation

MIMB Import Bridge from Apache Parquet File

Bridge Specifications

Vendor Apache
Tool Name Parquet File
Tool Version Parquet 1.x
Tool Web Site http://parquet.apache.org/
Supported Methodology [File System] Data Store (NoSQL / Hierarchical, Physical Data Model) via Java API on PARQUET File

SPECIFICATIONS
Tool: Apache / Parquet File version Parquet 1.x via Java API on PARQUET File
See http://parquet.apache.org/
Metadata: [File System] Data Store (NoSQL / Hierarchical, Physical Data Model)
Component: Parquet version 11.0.0

DISCLAIMER
This bridge requires internet access to https://repo.maven.apache.org/maven2/ (and exceptionally a few other tool sites)
in order to download the necessary third party software libraries into $HOME/data/download/MIMB/
- If https fails, the bridge then tries with http.
- If a proxy is used to access internet, you must configure that proxy in the JRE (see the -j option in the Miscellaneous parameter).
- If the bridge does not have access to internet, that directory can be copied from another server with internet access.
By running this bridge, you hereby acknowledge responsibility for the license terms and any potential security vulnerabilities from these downloaded third party software libraries.

OVERVIEW
This bridge imports metadata from Parquet files using a Java API.
Note that this bridge is not performing any data driven metadata discovery, but instead reading the schema definition at the footer (bottom) of the Parquet file. Therefore, this bridge needs to load the entire Parquet file to reach the schema definition at the end.

If the Parquet file is not compressed, there are no file size limit as the bridge automatically skips the data portion until the footer (although this may take time on large Parquet files). However, if the Parquet file is compressed, then the bridge needs to download the entire file to uncompress it to start with. Therefore, in such case, there is a default file size limit of 10 MB (any bigger files will be ignored), however this limit can be increased in in the Miscellaneous parameter.

This bridge detects the following standard Parquet data types:
as defined in https://parquet.apache.org/documentation/latest

BOOLEAN: 1 bit boolean
INT32: 32 bit signed ints
INT64: 64 bit signed ints
INT96: 96 bit signed ints
FLOAT: IEEE 32-bit floating point values
DOUBLE: IEEE 64-bit floating point values
BYTE_ARRAY: arbitrarily long byte arrays.

Please refer to the individual parameter's tool tips for more detailed examples.


Bridge Parameters

Parameter Name Description Type Values Default Scope
File Path to file to import FILE *.*   Mandatory
Miscellaneous INTRODUCTION
Specify miscellaneous options starting with a dash and optionally followed by parameters, e.g.
-connection.cast MyDatabase1="SQL Server"
Some options can be used multiple times if applicable, e.g.
-connection.rename NewConnection1=OldConnection1 -connection.rename NewConnection2=OldConnection2;
As the list of options can become a long string, it is possible to load it from a file which must be located in ${MODEL_BRIDGE_HOME}\data\MIMB\parameters and have the extension .txt. In such case, all options must be defined within that file as the only value of this parameter, e.g.
ETL/Miscellaneous.txt

JAVA ENVIRONMENT OPTIONS
-java.memory <Java Memory's maximum size> (previously -m)

1G by default on 64bits JRE or as set in conf/conf.properties, e.g.
-java.memory 8G
-java.memory 8000M

-java.parameters <Java Runtime Environment command line options> (previously -j)

This option must be the last one in the Miscellaneous parameter as all the text after -java.parameters is passed "as is" to the JRE, e.g.
-java.parameters -Dname=value -Xms1G
The following option must be set when a proxy is used to access internet (this is critical to access https://repo.maven.apache.org/maven2/ (and exceptionally a few other tool sites) in order to download the necessary third party software libraries.
-java.parameters -Dhttp.proxyHost=127.0.0.1 -Dhttp.proxyPort=3128 -Dhttps.proxyHost=127.0.0.1 -Dhttps.proxyPort=3128 -Dhttp.proxyUser=user -Dhttp.proxyPassword=pass -Dhttps.proxyUser=user -Dhttps.proxyPassword=pass

-java.executable <Java Runtime Environment full path name> (previously -jre)

It can be an absolute path to javaw.exe on Windows or a link/script path on Linux, e.g.
-java.executable "c:\Program Files\Java\jre1.8.0_211\bin\javaw.exe"

-environment.variable <name>=<value> (previously -v)

None by default, e.g.
-environment.variable var2="value2 with spaces"

MODEL IMPORT OPTIONS
-model.name <model name>

Override the model name, e.g.
-model.name "My Model Name"

-prescript <script name>

The script must be located in the bin directory, and have .bat or .sh extension.
The script path must not include any parent directory symbol (..).
The script should return exit code 0 to indicate success, or another value to indicate failure.
For example:
-prescript "script.bat arg1 arg2"

-cache.clear

Clears the cache before the import, and therefore will run a full import without incremental harvesting.
Warning: this is a system option managed by the application calling the bridge and should not be set by users.

-backup <directory>

Full path of an empty directory to save the metadata input files for further troubleshooting.

DATA CONNECTION OPTIONS
Data Connections are produced by the import bridges typically from ETL/DI and BI tools to refer to the source and target data stores they use. These data connections are then used by metadata management tools to connect them (metadata stitching) to their actual data stores (e.g. databases, file system, etc.) in order to produce the full end to end data flow lineage and impact analysis. The name of each data connection is unique by import model. The data connection names used within DI/BI design tools are used when possible, otherwise connection names are generated to be short but meaningful such as the database / schema name, the file system path, or Uniform Resource Identifier (URI). The following options allows to manipulate connections. These options replaces the legacy options -c, -cd, and -cs.

-connection.cast ConnectionName=ConnectionType

Casts a generic database connection (e.g. ODBC/JDBC) to a precise database type (e.g. ORACLE) for SQL Parsing, e.g.
-connection.cast "My Database"="SQL SERVER".
The list of supported data store connection types includes:
ACCESS
CASSANDRA
DB2
DENODO
HIVE
MYSQL
NETEZZA
ORACLE
POSTGRESQL
PRESTO
REDSHIFT
SALESFORCE
SAP HANA
SNOWFLAKE
SQL SERVER
SYBASE
TERADATA
VECTORWISE
VERTICA

-connection.rename OldConnection=NewConnection

Renames an existing connection to a new name, e.g.
-connection.rename OldConnectionName=NewConnectionName
Multiple existing database connections can be renamed and merged into one new database connection, e.g.
-connection.rename MySchema1=MyDatabase -connection.rename MySchema2=MyDatabase

-connection.split oldConnection.Schema1=newConnection

Splits a database connection into one or multiple database connections.
A single database connection can be split into one connection per schema, e.g.
-connection.split MyDatabase
All database connections can be split into one connection per schema, e.g.
-connection.split *
A database connection can be explicitly split creating a new database connection by appending a schema name to a database, e.g.
-connection.split MyDatabase.schema1=MySchema1

-connection.map DestinationPath=SourcePath

Maps a source path to destination path. This is useful for file system connections when different paths points to the same object (directory or file).
On Hadoop, a process can write into a CSV file specified with the HDFS full path, but another process reads from a HIVE table implemented (external) by the same file specified using a relative path with default file name and extension, e.g.
-connection.map hdfs://host:8020/users/user1/folder/file.csv=/user1/folder
On Linux, a given directory (or file) like /data can be referred to by multiple symbolic links like /users/john and /users/paul, e.g.
-connection.map /users/John=/data -connection.map /users/paul=/data
On Windows, a given directory like C:\data can be referred to by multiple network drives like M: and N:, e.g.
-connection.map M:\=C:\data -connection.map N:\=C:\data

-connection.casesensitive ConnectionName

Overrides the default case insensitive matching rules for the object identifiers inside the specified connection, provided the detected type of the data store by itself supports this configuration (e.g. Microsoft SQL Server, MySql etc.), e.g.
-connection.casesensitive "My Database"

FILE SYSTEM OPTIONS
-file.encoding <Encoding value>

Uses the encoding value to read the text files (e.g. delimited and fixed width).
The supported languages are listed below with the actual encoding value between parentheses at the end of each line, e.g.
-file.encoding shift_jis

Central and Eastern European (iso-8859-2)
Central and Eastern European (windows-1250)
Chinese Traditional (big5)
Chinese Simplified (GB18030)
Chinese Simplified (GB2312)
Cyrillic (iso-8859-5)
Cyrillic (windows-1251)
DOS (ibm-850)
Greek (iso-8859-7)
Greek (windows-1253)
Hebrew (iso-8859-8)
Hebrew (windows-1255)
Japanese (shift_jis)
Korean (ks_c_5601-1987)
Thai (TIS620)
Thai (windows-874)
Turkish (iso-8859-9)
Turkish (windows-1254)
UTF 8 (utf-8)
UTF 16 (utf-16)
Western European (iso-8859-1)
Western European (iso-8859-15)
Western European (windows-1252)
Locale encoding
No encoding conversion

-processing.max.threads <number> (previously -tps)

Allows for parallel processing up to a maximum number of threads (by default 1), e.g.
-processing.max.threads 10

-processing.max.time <time> (previously -tl)

Sets a time limit for processing all files. Time can be specified in seconds, minutes, or hours, e.g.
-processing.max.time 3600s
-processing.max.time 60m
-processing.max.time 1h

-processing.max.files <number> (previously -fl)

Sets a maximum number of files to process (there are no limits by default), e.g.
-processing.max.files 100

-partitions.refresh (previously -fresh.partition.models)

Uses the latest modified files when processing partitions defined in Partitioned directories parameter.

-partitions.disable.detection (previously -disable.partitions.autodetection)

Disables the automatic partition detection (when "Partition directories" option is empty)

-cache.reuse (previously -skip.download)

Reuses what was already downloaded in the cache by disabling dependencies downloading.

-hadoop.key <Hadoop configuration options> (previously -hadoop)

Sets key values for the hadoop libraries (None by default), e.g.
-hadoop.key key1=val1;key2=val2

-path.substitute <path> <new path> (previously -subst)

Substitutes a root path by a new one, e.g.
-path.substitute K: C:\test

DELIMITED FILE OPTIONS
-delimited.disable.header.parsing (previously -delimited.no_header)

Disables the parsing of the header of delimited files (headers are parsed by default to detect field names).
Use this option if the delimited file has no header, or to disable the import of the header (if the field names are sensitive).

-delimited.ignore.top.rows <number> (previously -delimited.top_rows_skip)

Skips an number of rows at the top of delimited files (by default 0).
Use this option the the delimited files contains several rows of description at the beginning.
-delimited.ignore.top.rows 1

-delimited.add.separators <comma separated separators> (previously -delimited.extra_separators)

Adds extra possible separators when parsing delimited files.
By default, the detected separators include: ', (comma)' , '; (semicolon)', ': (colon)', '\t (tab)', '| (pipe)', '0x1 (ctrl+A)', 'BS (\u0008)'
Note that extra separators can be multi characters, e.g.
-delimited.add.separators ~,||,|~

PARQUET FILE OPTIONS
-parquet.max.compressed.size <value> (previously -parquet.compressed.max.size)

Ignores any parquet archive files with a compressed size bigger than the provided value (Default value is 10 000 000 bytes), e.g.
-parquet.compressed.max.size=10000000
STRING      

 

Bridge Mapping

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Last updated on Fri, 8 Jan 2021 17:33:53

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