Denys GolotiukUsing partitions in ClickhouseClickhouse supports table partitioning which can be useful in cases we deal with serial data and need to work only with a moving window of…Nov 29, 20222Nov 29, 20222
Denys GolotiukEstimating duplicates and deduplicating data in ClickhouseClickhouse has a way to quickly estimate number of duplicates in a table as well as remove duplicates so only unique rows remain. Popular…Nov 21, 20223Nov 21, 20223
Denys GolotiukHow to use window functions in MysqlUsing windows in Mysql is a way to query data based on a set of rows instead of a single row. This helps in comparative analysis, when we…Nov 11, 2022Nov 11, 2022
Denys GolotiukBig data exploratory data analysis with ClickhouseAny analysis starts with exploratory stage — when we try to understand the big picture of the data itself. We usually do things like…Nov 4, 2022Nov 4, 2022
Denys GolotiukData cleansing and preparation for analysis with Python and PandasAny data usually (always?) contain errors. In order to do accurate analysis and build efficient ML models, data needs to be cleansed prior…Nov 2, 20221Nov 2, 20221
Denys GolotiukOptimizing star-schema queries with IN queries and denormalizationMost data environments usually have 2 main groups of data objects. First — event based objects, usually organized into timeseries tables…Oct 31, 2022Oct 31, 2022
Denys GolotiukUsing projections to speedup queries in ClickhouseClickhouse is efficient enough so most analytical queries will execute fast in many cases without extra optimization activities. But, if…Oct 28, 20222Oct 28, 20222
Denys GolotiukWorking with JSON in ClickhouseThere’s plenty of cases when we can’t define data structure in advance due to its dynamic nature. Data objects can have different set of…Oct 26, 20221Oct 26, 20221
Denys GolotiukSolving systems of linear equations using matrices and PythonMatrices stay at the very basis of all math used for ML. Let’s understand why it is so and how matrices can be used to solve systems of…Oct 19, 2022Oct 19, 2022
Denys GolotiukUsing EXPLAIN in Mysql to analyze and improve query performanceMysql EXPLAIN statement lets us understand efficiency of our queries and grasp ideas on possible ways to optimize it. Just creating indexes…Oct 17, 20225Oct 17, 20225
