Site: Add upcoming talk at ApacheCon'21 and info about tutorial at BOSS21
diff --git a/site/community/index.md b/site/community/index.md
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+++ b/site/community/index.md
@@ -26,7 +26,9 @@
# Upcoming talks
-There are no upcoming talks at the moment. Stay tuned!
+## Building modern SQL query optimizers with Apache Calcite (Vladimir Ozerov)
+
+At [ApacheCon 2021](https://www.apachecon.com/acah2021/tracks/bigdatasql.html), September 22, 2021.
# Project Members
@@ -87,6 +89,13 @@
Watch some presentations and read through some slide decks about
Calcite, or attend one of the [upcoming talks](#upcoming-talks).
+## Apache Calcite Tutorial
+
+At [BOSS 2021](https://boss-workshop.github.io/boss-2021/), Copenhagen, Denmark, August 16, 2021;
+[[summary](https://github.com/zabetak/slides/blob/master/2021/boss-workshop/apache-calcite-tutorial.md)],
+[[slides](https://www.slideshare.net/StamatisZampetakis/apache-calcite-tutorial-boss-21)],
+[[pdf](https://github.com/zabetak/slides/blob/master/2021/boss-workshop/apache-calcite-tutorial.pdf)].
+
## An introduction to query processing & Apache Calcite
At [Calcite Virtual Meetup](https://www.meetup.com/Apache-Calcite/events/275461117/), January 20, 2021;
