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Extract Coordinates from the POM Helpful for build and integration environments, pipelines etc. Exctract the Project version from the pom.xml mvn org.apache.maven.plugins:maven-help-plugin:3.1.0:evaluate -Dexpression=project.version -q -DforceStdout Override a Property via local configuration e.g. to override the property xxx from your project’s pom.xml Create a directory .mvn in your project directory root Create a file named maven.config in this directory Insert -Dxxx=newvalue into the file to override this property Don’t forget to add .mvn to your .gitignore! ...

Data Normalizing Formula newVal = (oldVal-min) / (max-min) Ugly Scala Example package com.hascode import scala.collection.mutable.LinkedList object NormalizerExample extends App { val dataSet = LinkedList(1., 6.5, 3., 6.2, 20., 31.2, 50.2, 12., 0.24, 1.224, 2.2, 3.) for ((num, index) <- dataSet.zipWithIndex) { dataSet(index) = (num - dataSet.min) / (dataSet.max - dataSet.min) } println("Normalized: " + dataSet) } Normalized: LinkedList(0.01521216973578863, 0.12921819759798853, 0.05947594797769014, 0.12324029048767723, 0.3982240175619966, 0.6213992163469515, 1.0, 1.0, 0.07531115879828326, 0.40498283261802576, 0.7319742489270387, 1.0)

Use List of Parameters in Annotation-based Query Possible using MyBatis Dynamic SQL feature package com.hascode.example.mybatis; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Param; import org.apache.ibatis.annotations.Select; import java.util.List; @Mapper public interface SampleMapper { @Select({"<script>", "SELECT sample.bar", "FROM sampletable sample", "WHERE sample.id IN", "<foreach item='item' index='index' collection='ids'", "open='(' separator=',' close=')'>", "#{item}", "</foreach>", "</script>"}) List<Foo> getSamplesMatchingIds(@Param("ids") List<String> ids); } The mapper may now be used with a list of parameter objects: var samples = sampleMapper.getSamplesMatchingIds(List.of("24059e5b-aa07-424d-855e-50f499b8f697", "65140fc0-fc9f-42d2-9531-5e5d6caeba30")); Call a Procedure package com.hascode.example.mybatis; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Options; import org.apache.ibatis.annotations.Select; import org.apache.ibatis.mapping.StatementType; @Mapper public interface SampleMapper { @Select("CALL SCHEMA.CL.setScope(#{scope})") @Options(statementType = StatementType.CALLABLE) void setScope(int scope); } ...

Aggregate existing Labels MATCH (n) RETURN DISTINCT labels(n) Or unwinding label pairs MATCH (n) WITH DISTINCT labels(n) AS labels UNWIND labels AS label RETURN DISTINCT label ORDER BY label

The USE Methodology USE stands for Utilization, Saturation, and Errors. Developed by Brendan Gregg, it’s a low-level diagnostic tool for infrastructure and system resources. Utilization – How much of a resource is used? (e.g., 70% CPU) Saturation – Is the system over capacity? (e.g., CPU run queue) Errors – Are there hardware or system faults? (e.g., disk errors) Best for: Bottleneck analysis on servers, network, disk, memory Source: https://grafana.com/docs/grafana/latest/dashboards/build-dashboards/best-practices/ The RED Methodology RED focuses on service-level performance and is tailored for microservices and HTTP-based systems. ...

WordPress anonymize IP in comments Add as last line in theme’s functions.php: function wpb_remove_commentsip($comment_author_ip) { return '127.0.0.1'; } add_filter('pre_comment_user_ip','wpb_remove_commentsip'); WordPress remove version info Add as last line in theme’s functions.php: function remove_version_info() { return ''; } add_filter('the_generator', 'remove_version_info'); List of all WordPress Hooks

Administration & Configuration Connections Show Max Connections (value and source) SELECT setting, source, sourcefile, sourceline FROM pg_settings WHERE name = 'max_connections'; Set Max Connections ALTER system SET max_connections = 250; Kill Connections for a Database SELECT pg_terminate_backend(pid) FROM pg_catalog.pg_stat_activity -- we don't want to kill our own connection WHERE pid != pg_backend_pid() -- we don't want to kill connections to other databases AND datname = 'MYDATABASE' Show Statement Timeout Settings for All Users SELECT r.rolname, (SELECT unnest(s.setconfig) FROM pg_db_role_setting s WHERE s.setrole = r.oid AND s.setconfig::text LIKE '%statement_timeout%' LIMIT 1) AS statement_timeout FROM pg_roles r WHERE r.rolcanlogin ORDER BY r.rolname; ...

Virtual Environments Create and activate a venv python -m venv /path/to/new-env (1) source /path/to/new-env/bin/activate (2) 1 Creates a new virtual environment 2 Activate the new virtual environment Deactivate venv deactivate Save used dependencies to a file pip freeze > dependencies.txt Install dependencies from file pip install -r dependencies.txt Storing and fetching Credentials from the System Keyring I am using jaraco/keyring here: pip install keyring import keyring keyring.set_password("system", "db.sample.password", "xoxo") print(keyring.get_password("system", "db.sample.password")) ...

Installation Installing rustup first…​ install rustup via shell script curl --proto '=https' --tlsv1.2 https://sh.rustup.rs -sSf | sh install rustup via brew brew install rustup-init (1) rustup-init (2) Welcome to Rust! [...] Current installation options: default host triple: aarch64-apple-darwin default toolchain: stable (default) profile: default modify PATH variable: yes 1) Proceed with standard installation (default - just press enter) 2) Customize installation 3) Cancel installation 1 install rustup 2 install rust binaries and add them to paths etc…​ ...

SBT – Eclipse Plugin Add to your ~/.sbt/plugins/plugins.sbt addSbtPlugin("com.typesafe.sbteclipse" % "sbteclipse-plugin" % "2.1.1")