I am new to Apache Hadoop. I came across something Derby. What is the meaning of Metadata DB Derby. I heard it is some file system. But can anybody tell what exactly is it & its working?
1
There are 1 answers
Related Questions in HADOOP
- Can anyoone help me with this problem while trying to install hadoop on ubuntu?
- Hadoop No appenders could be found for logger (org.apache.hadoop.mapreduce.v2.app.MRAppMaster)
- Top-N using Python, MapReduce
- Spark Driver vs MapReduce Driver on YARN
- ERROR: org.apache.hadoop.fs.UnsupportedFileSystemException: No FileSystem for scheme "maprfs"
- can't write pyspark dataframe to parquet file on windows
- How to optimize writing to a large table in Hive/HDFS using Spark
- Can't replicate block xxx because the block file doesn't exist, or is not accessible
- HDFS too many bad blocks due to "Operation category WRITE is not supported in state standby" - Understanding why datanode can't find Active NameNode
- distcp throws java.io.IOException when copying files
- Hadoop MapReduce WordPairsCount produces inconsistent results
- If my data is not partitioned can that be why I’m getting maxResultSize error for my PySpark job?
- resource manager and nodemanager connectivity issues
- ERROR flume.SinkRunner: Unable to deliver event
- converting varchar(7) to decimal (7,5) in hive
Related Questions in HIVE
- Type Adapter for Offset in hive flutter
- HIVE Sql Date conversion
- How to set spark.executor.extraClassPath & spark.driver.extraClassPath in hive query without adding those in hive-site.xml
- Hive query on HUE shows different timestamp than programatically/on data
- descending order of data in hive using collect_set
- How to optimize writing to a large table in Hive/HDFS using Spark
- Spark SQL repartition before insert operation
- Alter datatype of complex type(array<struct>>) in hive
- SqlAlchemy connection to Hive using http thrift transport and basic auth
- Aggregate values into a new column while retaining the old column
- Is it possible to query MAPR hdfs/hive tables from Trino?
- Can we make a column having both partitioning and bucketing in hive?
- converting varchar(7) to decimal (7,5) in hive
- Extract all characters before numeric values in hive SQL
- Livy session to submit pyspark from HDFS
Related Questions in HDFS
- Can anyoone help me with this problem while trying to install hadoop on ubuntu?
- ERROR: org.apache.hadoop.fs.UnsupportedFileSystemException: No FileSystem for scheme "maprfs"
- How to optimize writing to a large table in Hive/HDFS using Spark
- Update hadoop hadoop-2.6.5 to haddop 3.x. Operation category WRITE is not supported in state standby
- Copy/Merge multiple HDFS files using Nifi Processor
- HDFS too many bad blocks due to "Operation category WRITE is not supported in state standby" - Understanding why datanode can't find Active NameNode
- distcp throws java.io.IOException when copying files
- ERROR flume.SinkRunner: Unable to deliver event
- Apache flume does not run hadoop 3.1.0 Flume 1.11
- Livy session to submit pyspark from HDFS
- ClickHouse Server Exception: Code: 210.DB::Exception: Fail to read from HDFS:
- Confluent HDFS Sink connector error while connecting HDFS to Hive
- Node Transitioned from NEW to UNHEALTHY and Attempting to remove non-existent node
- Error associated with Azure Datalake Gen2 and Hadoop connection
- How do I directly read files from HDFS using dask?
Popular Questions
- How do I undo the most recent local commits in Git?
- How can I remove a specific item from an array in JavaScript?
- How do I delete a Git branch locally and remotely?
- Find all files containing a specific text (string) on Linux?
- How do I revert a Git repository to a previous commit?
- How do I create an HTML button that acts like a link?
- How do I check out a remote Git branch?
- How do I force "git pull" to overwrite local files?
- How do I list all files of a directory?
- How to check whether a string contains a substring in JavaScript?
- How do I redirect to another webpage?
- How can I iterate over rows in a Pandas DataFrame?
- How do I convert a String to an int in Java?
- Does Python have a string 'contains' substring method?
- How do I check if a string contains a specific word?
Trending Questions
- UIImageView Frame Doesn't Reflect Constraints
- Is it possible to use adb commands to click on a view by finding its ID?
- How to create a new web character symbol recognizable by html/javascript?
- Why isn't my CSS3 animation smooth in Google Chrome (but very smooth on other browsers)?
- Heap Gives Page Fault
- Connect ffmpeg to Visual Studio 2008
- Both Object- and ValueAnimator jumps when Duration is set above API LvL 24
- How to avoid default initialization of objects in std::vector?
- second argument of the command line arguments in a format other than char** argv or char* argv[]
- How to improve efficiency of algorithm which generates next lexicographic permutation?
- Navigating to the another actvity app getting crash in android
- How to read the particular message format in android and store in sqlite database?
- Resetting inventory status after order is cancelled
- Efficiently compute powers of X in SSE/AVX
- Insert into an external database using ajax and php : POST 500 (Internal Server Error)
Hadoop's Namenode stores metadata regarding where a file is stored on HDFS. That is, when you put a file onto HDFS, it gets replicated 3 times (by default) and the Namenode keeps track of which 3 servers are hosting the file.
Hive's Metadata is separate from the Namenode's metadata. Hive's Metadata maintains locations of it's underlying partitions, tables, databases, etc. The table schemas are also stored in Hive's Metadata. Hive requires a database backend to maintain this metadata, Derby is simply the default embedded metastore for Hive.
See http://hortonworks.com/blog/hdfs-metadata-directories-explained/ and https://cwiki.apache.org/confluence/display/Hive/AdminManual+MetastoreAdmin