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https://issues.apache.org/jira/browse/HIVE-18192?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16345824#comment-16345824
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Sankar Hariappan commented on HIVE-18192:
-----------------------------------------
Added 06.patch with below changes.
1. Support ValidWriteIdList config string with multiple tables. Need to change
the format to include table name and separator as
follows.<table_name>:hwm:minWriteId:open1,open2:abort1,abort2$<table_name>:hwm...
2. Pass appropriate ValidWriteIdList string to ORCInputFormat without need to
get table name there. (As per Gopal’s suggestion)
Pending changes for this feature
# Cleaner for TXNS_TO_WRITE_ID table entries. Also, need to maintain the LWM
for each table write id.
# Update classes to use WriteID instead of TxnId as methods and variable names.
# Scripts to add Metastore tables for write id management. Add for other
non-derby databases too.
# Remove entries from TXNS_TO_WRITE_ID table when drop a table/database. Also,
split db and table names into 2 columns.
# CompactionTxnHandler cleanup COMPLETED_TXN_COMPONENTS based on highest write
id instead of highest txn id.
# Non-Acid to Acid conversion through alter table transaction property.
> Introduce WriteID per table rather than using global transaction ID
> -------------------------------------------------------------------
>
> Key: HIVE-18192
> URL: https://issues.apache.org/jira/browse/HIVE-18192
> Project: Hive
> Issue Type: Sub-task
> Components: HiveServer2, Transactions
> Affects Versions: 3.0.0
> Reporter: anishek
> Assignee: Sankar Hariappan
> Priority: Major
> Labels: ACID, DR, pull-request-available
> Fix For: 3.0.0
>
> Attachments: HIVE-18192.01.patch, HIVE-18192.02.patch,
> HIVE-18192.03.patch, HIVE-18192.04.patch, HIVE-18192.05.patch,
> HIVE-18192.06.patch
>
>
> To support ACID replication, we will be introducing a per table write Id
> which will replace the transaction id in the primary key for each row in a
> ACID table.
> The current primary key is determined via
> <original transaction id, bucketid , rowid>
> which will move to
> <original write id, bucketid, rowid>
> For each table modified by the given transaction will have a table level
> write ID allocated and a persisted map of global txn id -> to table -> write
> id for that table has to be maintained to allow Snapshot isolation.
> Readers should use the combination of ValidTxnList and
> ValidWriteIdList(Table) for snapshot isolation.
>
> [Hive Replication - ACID
> Tables.pdf|https://issues.apache.org/jira/secure/attachment/12903157/Hive%20Replication-%20ACID%20Tables.pdf]
> has a section "Per Table Sequences (Write-Id)" with more detials
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