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delta.enableDeletionVectors #474

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jayengee opened this issue Apr 15, 2024 · 14 comments
Open

delta.enableDeletionVectors #474

jayengee opened this issue Apr 15, 2024 · 14 comments

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@jayengee
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Issue

Running a simple load_as_pandas command against tables we've created in Databricks is returning an error suggesting that this library does not support tables with deletion vectors enabled, which could be the default setting for tables in Databricks

The logs suggest that a newer version of delta-sharing-spark would support this, but this library seems to be using 2.12:

pyspark --packages io.delta:delta-sharing-spark_2.12:0.6.4
. Are there plans to make this available/upgrade ?

Logs

>>> import delta_sharing
>>> config_path = "./delta-sharing-poc-config.share"
>>> table2_path = "delta_share_poc.product2.customer"
>>> df2 = delta_sharing.load_as_pandas(f"{config_path}#{table2_path}")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/delta_sharing.py", line 119, in load_as_pandas
    return DeltaSharingReader(
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/reader.py", line 89, in to_pandas
    response = self._rest_client.list_files_in_table(
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/rest_client.py", line 113, in func_with_retry
    raise e
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/rest_client.py", line 101, in func_with_retry
    return func(self, *arg, **kwargs)
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/rest_client.py", line 342, in list_files_in_table
    with self._post_internal(
  File "/Users/<user>/.pyenv/versions/3.9.13/lib/python3.9/contextlib.py", line 119, in __enter__
    return next(self.gen)
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/rest_client.py", line 441, in _request_internal
    raise HTTPError(message, response=e.response) from None
requests.exceptions.HTTPError: 400 Client Error: Bad Request for url: https://oregon.cloud.databricks.com/api/2.0/delta-sharing/metastores/988a4820-a048-40a3-9d85-e690d2a6b89c/shares/delta_share_poc/schemas/product2/tables/customer/query
 Response from server:
 { 'error_code': 'BAD_REQUEST',
  'message': '\n'
             'Table property\n'
             'delta.enableDeletionVectors\n'
             'is found in table version: 6.\n'
             'Here are a couple options to proceed:\n'
             ' 1. Use DBR version 14.1(14.2 for CDF and streaming) or higher '
             'or delta-sharing-spark with version 3.1 or higher and set option '
             '("responseFormat", "delta") to query the table.\n'
             ' 2. Contact your provider to ensure the table is shared with '
             'full history.\n'
             '[Trace Id: a3bec5eaa8e2156bde8aeee73db3d470]'}
>>>

The share for this recipient was set such that they had access to table history, which suggests that permissioning is not the issue here:
Screenshot 2024-04-15 at 13 48 14

When I disabled the associated property on the table by running ALTER TABLE delta_share_poc.product2.customer SET TBLPROPERTIES (delta.enableDeletionVectors = true);, the same load_as_pandas call is successful:

>>> df2 = delta_sharing.load_as_pandas(f"{config_path}#{table2_path}")
>>> df2.head()
   id                                             values
0   1                                   i dont like sand
1   2  its coarse and rough and irritating and it get...

Steps to reproduce

  1. Create table with delection vectors enabled
  2. Create delta-share for table
  3. Access delta-share for table using delta_sharing library
@aimtsou
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aimtsou commented Apr 16, 2024

Hi jayengee,

You are using a library version which does not support deletion vectors(0.6.4 and 2.12 is the scala version). From here,

“Delta Format Sharing” is newly introduced since delta-sharing-spark 3.1, which supports reading shared Delta tables with advanced Delta features such as deletion vectors and column mapping.

From the same link you can find the maven repository link with delta-sharing 3.1.0

@jayengee
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Author

Thanks for your response @aimtsou !

Sorry, I might be missing something basic here. From the 3.1.0 Delta release notes you shared I see links to delta-sharing-spark 2.12 and 2.13.

From the release notes:

This release of Delta delta-io/delta#2291 a new module called delta-sharing-spark which enables reading Delta tables shared using the Delta Sharing protocol in Apache Spark™. It is migrated from https://github.com/delta-io/delta-sharing/tree/main/spark repository to https://github.com/delta-io/delta/tree/master/sharing repository. Last release version of delta-sharing-spark is 1.0.4 from the previous location. Next release of delta-sharing-spark is with the current release of Delta which is 3.1.0.

Does this mean that this repo isn't what I should be using moving forward? Alternatively, am I not supposed to be installing via PyPi, and instead compile delta-sharing and delta-sharing spark on my end?

FWIW the latest release in this repo seems to be 1.0.4, which was released before the delta 3.1.0 release. PyPi also still points to 1.0.3

@aimtsou
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aimtsou commented Apr 17, 2024

Hi @jayengee,

You are confused and I understand that, believe I tried to read up on the repo and it is not being handled very well. Beware, I am not a maintainer so all is personal research while I setup the things on my side.

Sorry, I might be missing something basic here. From the 3.1.0 Delta release notes you shared I see links to delta-sharing-spark 2.12 and 2.13.

The 2.12 and 2.13 are Scala versions. Taking the 2.13 as example you can see all the versions by moving the directory up ie.

Does this mean that this repo isn't what I should be using moving forward?

I cannot reply that officially since I am not maintainer but both seem to be used, at least the one here until version 1.0.4 and for the description of the protocol. The documentation here, for the protocol points back to this repository. So for the moment we have a mix.

Alternatively, am I not supposed to be installing via PyPi, and instead compile delta-sharing and delta-sharing spark on my end?

There are several stuff:

  • Delta Sharing Server 1.0.4 which is if you want to run your own server, you do not need it as you have unity catalog enabled.
  • Delta Sharing Spark which is the jar file you need installed to your cluster. For DeletionVectors, you need Spark 3.5 and delta sharing spark 3.1.0, so a DBR version 14.x and onwards
  • Delta Sharing in pypi seems to be the a wrapper of the delta-sharing-spark as without it you cannot read tables (but this is an assumption as I have found no documentation and this why I opened this issue)

You can try also to read the remote dataset that delta.io offers with this version.

And then try with your dataset but for that you will need the delta-sharing-spark 3.1.0 and a DBR version that supports Spark 3.5.0.

I hope I resolved some of your questions.

@linzhou-db
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Collaborator

@jayengee thanks for the question.
@aimtsou thanks for the answer.

The versions for delta-sharing-server, delta-sharing python connector and delta-sharing-spark are independent with each other.

  • It is true that the latest delta-sharing-spark is 3.1.0, which is able to read shared DV tables.
  • The latest delta-sharing python connector is 1.0.3, but it uses the latest delta-sharing-spark installed on your machine when calling load_as_spark, not restricted to the python connector version.

We'll update our doc to make it more clear.

@jayengee
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Thanks both for the input!

@linzhou-db

The latest delta-sharing python connector is 1.0.3, but it uses the latest delta-sharing-spark installed on your machine when calling load_as_spark, not restricted to the python connector version
Understanding that the three different versions/packages are independent of one another, how is the delta-sharing-spark installed locally?

The path I had gone through initially was to simply run:

$ pip install delta-sharing

Then open up a python shell and run the previously provided commands

Given your last comment, I've also tried running this in pyspark shell locally:

$ pyspark --packages io.delta:delta-sharing-spark_2.13:3.1.0

However, I get the same error when calling load_as_pandas.

I get a different error when calling load_as_spark:

>>> delta_sharing.load_as_spark(f"{profile_path}#{share_name}.{table_path_2}")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/delta_sharing.py", line 159, in load_as_spark
    return df.load(url)
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/pyspark/sql/readwriter.py", line 307, in load
    return self._df(self._jreader.load(path))
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/pyspark/python/lib/py4j-0.10.9.7-src.zip/py4j/java_gateway.py", line 1322, in __call__
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/pyspark/errors/exceptions/captured.py", line 179, in deco
    return f(*a, **kw)
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/pyspark/python/lib/py4j-0.10.9.7-src.zip/py4j/protocol.py", line 326, in get_return_value
py4j.protocol.Py4JJavaError: An error occurred while calling o47.load.
: java.util.ServiceConfigurationError: org.apache.spark.sql.sources.DataSourceRegister: io.delta.sharing.spark.DeltaSharingDataSource Unable to get public no-arg constructor
	at java.base/java.util.ServiceLoader.fail(ServiceLoader.java:582)
	at java.base/java.util.ServiceLoader.getConstructor(ServiceLoader.java:673)
	at java.base/java.util.ServiceLoader$LazyClassPathLookupIterator.hasNextService(ServiceLoader.java:1233)
	at java.base/java.util.ServiceLoader$LazyClassPathLookupIterator.hasNext(ServiceLoader.java:1265)
	at java.base/java.util.ServiceLoader$2.hasNext(ServiceLoader.java:1300)
	at java.base/java.util.ServiceLoader$3.hasNext(ServiceLoader.java:1385)
	at scala.collection.convert.Wrappers$JIteratorWrapper.hasNext(Wrappers.scala:45)
	at scala.collection.Iterator.foreach(Iterator.scala:943)
	at scala.collection.Iterator.foreach$(Iterator.scala:943)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1431)
	at scala.collection.IterableLike.foreach(IterableLike.scala:74)
	at scala.collection.IterableLike.foreach$(IterableLike.scala:73)
	at scala.collection.AbstractIterable.foreach(Iterable.scala:56)
	at scala.collection.TraversableLike.filterImpl(TraversableLike.scala:303)
	at scala.collection.TraversableLike.filterImpl$(TraversableLike.scala:297)
	at scala.collection.AbstractTraversable.filterImpl(Traversable.scala:108)
	at scala.collection.TraversableLike.filter(TraversableLike.scala:395)
	at scala.collection.TraversableLike.filter$(TraversableLike.scala:395)
	at scala.collection.AbstractTraversable.filter(Traversable.scala:108)
	at org.apache.spark.sql.execution.datasources.DataSource$.lookupDataSource(DataSource.scala:629)
	at org.apache.spark.sql.execution.datasources.DataSource$.lookupDataSourceV2(DataSource.scala:697)
	at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:208)
	at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:186)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
	at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:374)
	at py4j.Gateway.invoke(Gateway.java:282)
	at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
	at py4j.commands.CallCommand.execute(CallCommand.java:79)
	at py4j.ClientServerConnection.waitForCommands(ClientServerConnection.java:182)
	at py4j.ClientServerConnection.run(ClientServerConnection.java:106)
	at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.NoClassDefFoundError: scala/collection/IterableOnce
	at java.base/java.lang.Class.getDeclaredConstructors0(Native Method)
	at java.base/java.lang.Class.privateGetDeclaredConstructors(Class.java:3137)
	at java.base/java.lang.Class.getConstructor0(Class.java:3342)
	at java.base/java.lang.Class.getConstructor(Class.java:2151)
	at java.base/java.util.ServiceLoader$1.run(ServiceLoader.java:660)
	at java.base/java.util.ServiceLoader$1.run(ServiceLoader.java:657)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.util.ServiceLoader.getConstructor(ServiceLoader.java:668)
	... 33 more
Caused by: java.lang.ClassNotFoundException: scala.collection.IterableOnce
	at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:476)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:589)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
	... 41 more

For context, I'm running these calls locally against a Databricks metastore, in order to POC a future use case where we would want to open up (share) tables from our Databricks metastore with users who don't have access to our Databricks workspaces. My hope is to figure out a playbook for them, which I had initially anticipated would be via just installing delta-sharing and being given a token/profile .share file

Thanks for your help!

@aimtsou
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aimtsou commented Apr 22, 2024

@jayengee:

I find your procedure correct. Although from the error I see that you miss a Java library which seems weird due to the fact that you try to bring it with the --packages flag.

Can you try to load in your local environment the remote dataset that delta.io offers with version 3.1.0.

Also can you try to add the following snippet at your code? Can you read the tables even with your profile file and dataset?

# Create a SharingClient.
client = delta_sharing.SharingClient(profile_file)

# List all shared tables.
print(client.list_all_tables())

@jayengee
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Author

Hi @aimtsou

Yep I thought that was odd as well.

Output below from where I list all tables from my side (pointed at Databricks), and also at the remote dataset from delta.io. In short, despite installing delta-sharing-spark 2.13:3.1.0, and being able to list the tables, I can't read from them - I get the same error about an unsupported feature. However, I am able to read from the remote dataset from delta.io

$ pyspark --packages io.delta:delta-sharing-spark_2.13:3.1.0
Welcome to
      ____              __
     / __/__  ___ _____/ /__
    _\ \/ _ \/ _ `/ __/  '_/
   /__ / .__/\_,_/_/ /_/\_\   version 3.5.1
      /_/

Using Python version 3.9.13 (main, Jun 28 2022 16:47:28)
Spark context Web UI available at http://172.16.11.113:4040
Spark context available as 'sc' (master = local[*], app id = local-1713903316429).
SparkSession available as 'spark'.
>>> import delta_sharing
>>> profile_path = "/Users/<user>/Downloads/config.share"
>>> share_name = "delta_share_poc"
>>> table_path_2 = 'product2.customer'
>>>
>>> # Create a SharingClient.
>>> client = delta_sharing.SharingClient(profile_path)
>>>
>>> # List all shared tables.
>>> print(client.list_all_tables())
[Table(name='customer', share='delta_share_poc', schema='product2')]
>>>
>>> delta_sharing.load_as_pandas(f"{profile_path}#{share_name}.{table_path_2}", limit=10)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/delta_sharing.py", line 122, in load_as_pandas
    return DeltaSharingReader(
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/reader.py", line 89, in to_pandas
    response = self._rest_client.list_files_in_table(
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/rest_client.py", line 113, in func_with_retry
    raise e
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/rest_client.py", line 101, in func_with_retry
    return func(self, *arg, **kwargs)
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/rest_client.py", line 342, in list_files_in_table
    with self._post_internal(
  File "/Users/<user>/.pyenv/versions/3.9.13/lib/python3.9/contextlib.py", line 119, in __enter__
    return next(self.gen)
  File "/Users/<user>/.local/share/virtualenvs/code-QImT9lvn/lib/python3.9/site-packages/delta_sharing/rest_client.py", line 441, in _request_internal
    raise HTTPError(message, response=e.response) from None
requests.exceptions.HTTPError: 400 Client Error: Bad Request for url: https://oregon.cloud.databricks.com/api/2.0/delta-sharing/metastores/988a4820-a048-40a3-9d85-e690d2a6b89c/shares/delta_share_poc/schemas/product2/tables/customer/query
 Response from server:
 { 'details': [ { '@type': 'type.googleapis.com/google.rpc.ErrorInfo',
                 'domain': 'data-sharing.databricks.com',
                 'metadata': { 'optionStr': 'For DeletionVectors, use DBR with '
                                            'version 14.1(14.2 for CDF and '
                                            'streaming) or higher, or '
                                            'delta-sharing-spark with version '
                                            '3.1 or higher, and set option '
                                            '("responseFormat", "delta") to '
                                            'query the table. ',
                               'tableFeatures': 'delta.enableDeletionVectors',
                               'versionStr': ' version: 10.'},
                 'reason': 'DS_UNSUPPORTED_FEATURES'}],
  'error_code': 'INVALID_PARAMETER_VALUE',
  'message': 'Table features delta.enableDeletionVectors are found in table '
             'version: 10. For DeletionVectors, use DBR with version 14.1(14.2 '
             'for CDF and streaming) or higher, or delta-sharing-spark with '
             'version 3.1 or higher, and set option ("responseFormat", '
             '"delta") to query the table. '}
>>>
>>> profile_path_2 = "/Users/<user>/Downloads/open-datasets.share"
>>> client_2 = delta_sharing.SharingClient(profile_path_2)
>>> print(client_2.list_all_tables())
[Table(name='COVID_19_NYT', share='delta_sharing', schema='default'), Table(name='boston-housing', share='delta_sharing', schema='default'), Table(name='flight-asa_2008', share='delta_sharing', schema='default'), Table(name='lending_club', share='delta_sharing', schema='default'), Table(name='nyctaxi_2019', share='delta_sharing', schema='default'), Table(name='nyctaxi_2019_part', share='delta_sharing', schema='default'), Table(name='owid-covid-data', share='delta_sharing', schema='default')]
>>> delta_sharing.load_as_pandas(f"{profile_path_2}#delta_sharing.default.COVID_19_NYT", limit=10)
         date    county    state   fips  cases  deaths
0  2021-01-10  Washakie  Wyoming  56043    804      21
1  2021-01-10    Weston  Wyoming  56045    485       4
2  2021-01-11   Autauga  Alabama   1001   4902      55
3  2021-01-11   Baldwin  Alabama   1003  15417     173
4  2021-01-11   Barbour  Alabama   1005   1663      35
5  2021-01-11      Bibb  Alabama   1007   2060      48
6  2021-01-11    Blount  Alabama   1009   5080      77
7  2021-01-11   Bullock  Alabama   1011    957      28
8  2021-01-11    Butler  Alabama   1013   1637      57
9  2021-01-11   Calhoun  Alabama   1015  10537     178
>>>

@john-grassroots
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I'm seeing the same error message reported above when I attempt to read tables inside Databricks I've shared to myself that have deletion vectors enabled. Actually, slightly different wording in error message but same error number and general gist of message (see below).

If I disable deletion vectors temporarily, I am able to read them via load_as_pandas()

I am able to read all the tables in the delta.io remote dataset - but question whether any of them have deletion vectors enabled.

Note: I'm running via Python rather than Spark Console.

Versions I'm running are...

Name: delta-sharing
Version: 1.0.5 (latest)

Name: databricks-spark
Version: 3.2.0 (latest)

Name: databricks-connect
Version: 14.3.2 (latest)

"delta-sharing-spark" not installed (pip show doesn't find - pypi doesn't list)


SHOW TBLPROPERTIES catalog.schema.table;

ALTER TABLE catalog.schema.table
SET TBLPROPERTIES ('delta.enableDeletionVectors' = false);


{ 'details': [ { '@type': 'type.googleapis.com/google.rpc.ErrorInfo',
'domain': 'data-sharing.databricks.com',
'metadata': { 'dsError': 'DS_UNSUPPORTED_DELTA_TABLE_FEATURES',
'optionStr': 'For DeletionVectors, use DBR with '
'version 14.1(14.2 for CDF and '
'streaming) or higher, or '
'delta-sharing-spark with version '
'3.1 or higher, and set option '
'("responseFormat", "delta") to '
'query the table. Or ask your '
'provider to disable '
'DeletionVectors with\n'
' (ALTER TABLE <table_name> SET ' 'TBLPROPERTIES ' '(delta.enableDeletionVectors=false)),\n'
' rewrite it without Deletion '
'Vectors (REORG TABLE ' '<table_name> APPLY(PURGE)).',
'tableFeatures': 'delta.enableDeletionVectors',
'versionStr': ' version: 6.'},
'reason': 'DS_UNSUPPORTED_DELTA_TABLE_FEATURES'}],
'error_code': 'INVALID_PARAMETER_VALUE',
'message': 'DS_UNSUPPORTED_DELTA_TABLE_FEATURES: Table features '
'delta.enableDeletionVectors are found in table version: 6. For '
'DeletionVectors, use DBR with version 14.1(14.2 for CDF and '
'streaming) or higher, or delta-sharing-spark with version 3.1 or '
'higher, and set option ("responseFormat", "delta") to query the '
'table. Or ask your provider to disable DeletionVectors with\n'
' (ALTER TABLE <table_name> SET TBLPROPERTIES ' '(delta.enableDeletionVectors=false)),\n'
' rewrite it without Deletion Vectors (REORG TABLE <table_name> ' 'APPLY(PURGE)).'}

@aimtsou
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aimtsou commented May 21, 2024

@john-grassroots:

"delta-sharing-spark" not installed (pip show doesn't find - pypi doesn't list)

Delta sharing spark is a jar file that you give to your spark context. If you are using azure you do not need to install it, in your cluster.
You are saying that you are running databricks but you do not mention which version.

@john-grassroots
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Hey @aimtsou - thanks for your comment.

We're on AWS Databricks. When we're running non-serverless compute clusters we're generally on 14.3 LTS.

I don't see any reference to SparkContext in either of the python examples from the project.

The readme does state you should be passing delta-sharing-spark but the python example (which is the way we're running) does not have any mention of delta-sharing-spark.

In my case, I'm sharing a few tables to myself. Those tables are part of a share defined on AWS Databricks. My client code is running on my local machine via python. We're developing some example code to distribute to partners who we intend to share data with via Delta Sharing.

I haven't moved on from Python to PySpark examples as I've run into a few issues with the Python examples I'm working through (this one and another with CDF Timestamps)

If I'm not missing something obvious, I think I'm experiencing the same error here that @jayengee is.

From README.md

To run the example of PySpark in Python run spark-submit --packages io.delta:delta-sharing-spark_2.12:0.6.2 ./python/quickstart_spark.py
To run the example of pandas DataFrame in Python run python3 ./python/quickstart_pandas.py

@aimtsou
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aimtsou commented May 21, 2024

Hey @aimtsou - thanks for your comment.

We're on AWS Databricks. When we're running non-serverless compute clusters we're generally on 14.3 LTS.

I don't see any reference to SparkContext in either of the python examples from the project.

So if I understand well you have enabled a share from your Databricks Unity Catalog. These examples are old, they are good for starting but do not cover the latest features ie: DeletionVectors

The readme does state you should be passing delta-sharing-spark but the python example (which is the way we're running) does not have any mention of delta-sharing-spark.

In my case, I'm sharing a few tables to myself. Those tables are part of a share defined on AWS Databricks. My client code is running on my local machine via python. We're developing some example code to distribute to partners who we intend to share data with via Delta Sharing.

I believe the spark session that you will start needs to have delta-sharing-spark >=3.1.0
If I understand your use case you have created a share from your unity catalog and you want to share it to somebody without access to databricks (so the open protocol)

I will use the MS Docs because it has some good examples for the open protocol. If you go to deletion vectors you will see you need delta-sharing-spark 3.1.0 at least. Now the most interesting next section is about pandas and it does not refer anything about Deletion Vectors although it provides an example with CDF. I believe deletion vectors are not supported in load_as_pandas but I will make a test using a new delta table.

I haven't moved on from Python to PySpark examples as I've run into a few issues with the Python examples I'm working through (this one and another with CDF Timestamps)

If I'm not missing something obvious, I think I'm experiencing the same error here that @jayengee is.

From README.md

To run the example of PySpark in Python run spark-submit --packages io.delta:delta-sharing-spark_2.12:0.6.2 ./python/quickstart_spark.py
To run the example of pandas DataFrame in Python run python3 ./python/quickstart_pandas.py

spark-submit --packages io.delta:delta-sharing-spark_2.12:3.1.0 ./python/quickstart_spark.py
For me even better would be to run: pyspark --packages io.delta:delta-sharing-spark_2.12:3.1.0

Then use the interactive shell, to try to load the tables in spark once with with DeletionVectors as true and one as false
If it loads it confirms my theory that with deletion vectors you can just load as spark and then you need to convert to pandas.

I will make some tests on my own and let you know.

For sure the docs and the examples need more updates

@john-grassroots
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john-grassroots commented May 21, 2024

Thanks @aimtsou - I'll take a look tomorrow at the Spark stuff.

To answer your questions above... Yes, we're on Databricks utilizing Unity Catalog and we've created a Delta Share there in that environment.

I've shared that data with myself and I'm consuming it outside of Databricks as that will be the scenario most of our clients and partners will be utilizing.

That share contains several test cases... Tables with delete vectors enables, with delete vectors disabled, and with change data feed enabled.

I can verify that I'm currently running the Python test project directly from VSCode and I'm not issuing any spark-submit commands from the terminal.

For tables where deletion vectors are enabled, when issuing the load_as_pandas method I get the error I mentioned above which is the same error @jayengee initially reported.

If I disable deletion vectors for that table the error goes away.

As @jayengee pointed out, there is an option to make enablement of deletion vectors enabled by default so explicitly disabling them isn't the solution.

I'm also not sure that first creating the dataframe in spark and then converting to pandas is the solution although it may do as a temporary workaround but forcing a consumer to go one route when deletion vectors are enabled and another when they're not feels like an anti-pattern.

I'll report back tomorrow when I get into Spark.

Thanks!

@linzhou-db
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Hi @john-grassroots @jayengee ,
There are some issues related to the local spark and java packages, which I'm not sure exactly what packages are related.

But we are actively working on native support in load_as_pandas() to read shared Tables with deletion vectors. We'll make a release note once it's ready.

@olegtyshcneko
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@linzhou-db any progress on load_as_pandas? We experience same error in our project with 1.0.5 package.

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