# HG changeset patch
# User Richard Westhaver <ellis@rwest.io>
# Date 1722062734 14400
# Node ID 6ac37a61456a27fbb4474ace491e9a8eedbbf122
# Parent  d543f73892d3a6d21cb7a7b31c9ba6ef67bed7b6
bump

diff -r d543f73892d3 -r 6ac37a61456a parquet-parsing.org
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parquet-parsing.org	Sat Jul 27 02:45:34 2024 -0400
@@ -0,0 +1,38 @@
+* DAT/PARQUET
+https://github.com/apache/parquet-format
+https://github.com/apache/parquet-format/blob/master/src/main/thrift/parquet.thrift
+https://github.com/apache/parquet-testing
+https://github.com/apache/parquet-java
+** glossary
+- block :: same as HDFS block
+- file :: file metadata is required, data is not
+- row-group :: a logical horizontal partitioning of the data into
+  rows. no physical rep is guaranteed for row-group
+- column-chunk :: a chunk of the data for a particular column
+- page :: column chunks are divided into pages. a page is conceptually
+  indivisible in terms of compression/encoding. multiple page types
+  can be interleaved in a column chunk.
+
+Files consists of 1+ row-groups. A row-group contains exactly one
+column chunk per column. Column chunks contain one or more pages.
+
+** format summary
+#+begin_example
+  4-byte magic number "PAR1"
+  <Column 1 Chunk 1>
+  <Column 2 Chunk 1>
+  ...
+  <Column N Chunk 1>
+  <Column 1 Chunk 2>
+  <Column 2 Chunk 2>
+  ...
+  <Column N Chunk 2>
+  ...
+  <Column 1 Chunk M>
+  <Column 2 Chunk M>
+  ...
+  <Column N Chunk M>
+  File Metadata
+  4-byte length in bytes of file metadata (little endian)
+  4-byte magic number "PAR1"
+#+end_example
diff -r d543f73892d3 -r 6ac37a61456a q-notes.org
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/q-notes.org	Sat Jul 27 02:45:34 2024 -0400
@@ -0,0 +1,33 @@
+* Queries
+Q --- Query languages
+
+EQL = Event Query Language
+SQL = Structured Query Language
+LQL = Logical Query Language
+GQL = Graph Query Language
+
+refs:
+https://tdop.github.io/
+https://howqueryengineswork.com/01-what-is-a-query-engine.html
+https://paperhub.s3.amazonaws.com/dace52a42c07f7f8348b08dc2b186061.pdf
+https://en.wikipedia.org/wiki/Graph_Query_Language
+https://code.kx.com/q
+https://docs.xtdb.com/reference/main/xtql/queries.html
+https://neo4j.com/docs/cypher-manual
+https://eql.readthedocs.io/en/latest/
+https://clojure.github.io/clojure-contrib/doc/datalog.html
+https://www.researchgate.net/publication/2850953_Soft_Stratification_for_Magic_Set_Based_Query_Evaluation_in_Deductive_Databases
+http://sieve.info/
+https://www.researchgate.net/publication/221542994_SARI-SQL_Event_query_language_for_event_analysis
+https://www.elastic.co/guide/en/elasticsearch/reference/current/eql.html
+https://www.youtube.com/watch?v=8XUutFBbUrg
+https://www.scryer.pl/
+https://github.com/inconvergent/cl-grph
+https://jakewheat.github.io/sql-overview/
+https://github.com/ronsavage/SQL
+https://web.csulb.edu/colleges/coe/cecs/dbdesign/dbdesign.php
+https://github.com/nikodemus/screamer
+https://github.com/defunkydrummer/cl-gambol
+https://www.lispworks.com/products/knowledgeworks.html
+https://namin.seas.harvard.edu/files/namin/files/sql2c_jfp.pdf
+https://scala-lms.github.io/tutorials/query.html