Re: PATCH: logical_work_mem and logical streaming of large in-progress transactions
Amit Kapila <amit.kapila16@gmail.com>
Commits
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the thread's linked commits as JSON, with link sources.
API reference →
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Tighten the concurrent abort check during decoding.
- 2ce353fc1902 14.0 landed
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Improve hash_create()'s API for some added robustness.
- b3817f5f7746 14.0 landed
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Use HASH_BLOBS for xidhash.
- a1b8aa1e4eec 14.0 landed
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Fix initialization of RelationSyncEntry for streaming transactions.
- 69bd60672af6 14.0 landed
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Remove unused function declaration in logicalproto.h.
- ddd5f6d2609b 14.0 landed
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Add additional tests to test streaming of in-progress transactions.
- 58b5ae9d62bd 14.0 landed
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Fix inline marking introduced in commit 464824323e.
- ac15b499f7f9 14.0 landed
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Add support for streaming to built-in logical replication.
- 464824323e57 14.0 landed
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Fix the SharedFileSetUnregister API.
- 4ab77697f67a 14.0 landed
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Fix comment in procarray.c
- 77c7267c37f7 14.0 cited
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Suppress compiler warning in non-cassert builds.
- e942af7b8261 14.0 cited
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Extend the BufFile interface.
- 808e13b282ef 14.0 landed
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Mark a few logical decoding related variables with PGDLLIMPORT.
- b48cac3b10a0 14.0 landed
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Implement streaming mode in ReorderBuffer.
- 7259736a6e5b 14.0 landed
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Extend the logical decoding output plugin API with stream methods.
- 45fdc9738b36 14.0 landed
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WAL Log invalidations at command end with wal_level=logical.
- c55040ccd017 14.0 landed
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Immediately WAL-log subtransaction and top-level XID association.
- 0bead9af484c 14.0 landed
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Allow logical replication to transfer data in binary format.
- 9de77b545313 14.0 cited
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Only superuser can set sslcert/sslkey in postgres_fdw user mappings
- cebf9d6e6ee1 13.0 cited
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Track statistics for spilling of changes from ReorderBuffer.
- 9290ad198b15 13.0 landed
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Add logical_decoding_work_mem to limit ReorderBuffer memory usage.
- cec2edfa7859 13.0 landed
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logical decoding: process ASSIGNMENT during snapshot build
- bac2fae05c77 13.0 cited
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Emit invalidations to standby for transactions without xid.
- c6ff84b06a68 9.6.0 cited
On Wed, Jan 8, 2020 at 1:12 PM Dilip Kumar <dilipbalaut@gmail.com> wrote: > > I have observed one more design issue. > Good observation. > The problem is that when we > get a toasted chunks we remember the changes in the memory(hash table) > but don't stream until we get the actual change on the main table. > Now, the problem is that we might get the change of the toasted table > and the main table in different streams. So basically, in a stream, > if we have only got the toasted tuples then even after > ReorderBufferStreamTXN the memory usage will not be reduced. > I think we can't split such changes in a different stream (unless we design an entirely new solution to send partial changes of toast data), so we need to send them together. We can keep a flag like data_complete in ReorderBufferTxn and mark it complete only when we are able to assemble the entire tuple. Now, whenever, we try to stream the changes once we reach the memory threshold, we can check whether the data_complete flag is true, if so, then only send the changes, otherwise, we can pick the next largest transaction. I think we can retry it for few times and if we get the incomplete data for multiple transactions, then we can decide to spill the transaction or maybe we can directly spill the first largest transaction which has incomplete data. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com