SPOILER: I need to say that the release 2.8 will be published after New Year and all answers will be related to the new release.
If we talk to 2.8 release (the last update of ML functionality in master and release branch) +++ I assume that I would start by extracting features from my JSON records in a cache into a vectorizer - how does this impact memory usage? +++ The answer is here: https://apacheignite.readme.io/docs/ml-partition-based-dataset The cache will be in memory and additional data will be located in heap too(but not in caches but near) Of course, more memory is required (depends on training algorithm) If heap is small you have a chance to get and OOM +++Are there any built-in algorithms or recommended strategies for sampling+++ Please have a look here https://github.com/apache/ignite/blob/master/examples/src/main/java/org/apache/ignite/examples/ml/tutorial/Step_7_Split_train_test.java You could use the same mechanism to get the random sample But the have no sampling tool as is to get the sample rows from cache. It is not a part of ML functionality now. +++ Are there any dataset statistical functions like those provided by Python's ML libraries, for high-level evaluation of specific features in a dataset (to assess things like missing-data, cardinality, min-max, mean, mode, standard-deviation, percentiles, etc)? +++ We are not manipulate directly the data in caches, the build new data in new format for training purposes, but we doesn't support in ML pandas-like operations. We have preprocessing algorithms, but they could be used as a first step in training Pipeline https://apacheignite.readme.io/docs/preprocessing Hope that in 2.9 summary for the dataset and a few stats (like described above) will be added. +++ - Is there any doc/video tutorial that would provide a guide for the complete workflow pipeline for an ML example (encompassing the abovementioned operations)? +++ First of all, please have a look to the Titanic Tutorial https://github.com/apache/ignite/tree/master/examples/src/main/java/org/apache/ignite/examples/ml/tutorial and another examples https://github.com/apache/ignite/tree/master/examples/src/main/java/org/apache/ignite/examples/ml Also a few videos are available in my channel https://www.youtube.com/watch?v=3CmnV6IQtTw https://www.youtube.com/watch?v=DmoMBsiHxf8 Jose, great questions, hope to share more docs and papers about Ignite ML after New Year and 2.8 release. -- Sent from: http://apache-ignite-users.70518.x6.nabble.com/